2,2-difluoropropionamide derivatives of bardoxolone methyl, polymorphic forms and methods of use thereof

ABSTRACT

The present invention relates generally to the compound:
     N-((4aS,6aR,6bS,8aR,12aS,14aR,14bS)-11-cyano-2,2,6a,6b,9,9,12a-heptamethyl-10,14-dioxo-1,2,3,4,4a,5,6,6a,6b,7,8,8a,9,10,12a,14,14a,14b-octadecahydropicen-4a-yl)-2,2-difluoropropanamide,
 
polymorphic forms thereof, methods for preparation and use thereof, pharmaceutical compositions thereof, and kits and articles of manufacture thereof.

The present application claims the benefit of priority to U.S. Provisional Application No. 61/780,444, filed on Mar. 13, 2013, U.S. Provisional Application No. 61/775,288, filed on Mar. 8, 2013, and U.S. Provisional Application No. 61/687,669, filed on Apr. 27, 2012; the entire contents of each are herein incorporated by reference.

Pursuant to 37 C.F.R. 1.821(c), a sequence listing is submitted herewith as an ASCII compliant text file named “REATP0073US_ST25,” created on Apr. 24, 2013 and having a size of ˜6 kilobytes. The content of the aforementioned file is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

I. Field of the Invention

The present invention relates generally to the compound:

-   N-((4aS,6aR,6bS,8aR,12aS,14aR,14bS)-11-cyano-2,2,6a,6b,9,9,12a-heptamethyl-10,14-dioxo-1,2,3,4,4a,5,6,6a,6b,7,8,8a,9,10,12a,14,14a,14b-octadecahydropicen-4a-yl)-2,2-difluoropropanamide,     also referred to herein as RTA 408, 63415, or PP415. The present     invention also relates to polymorphic forms thereof, methods for     preparation and use thereof, pharmaceutical compositions thereof,     and kits and articles of manufacture thereof.

II. Description of Related Art

The anti-inflammatory and anti-proliferative activity of the naturally occurring triterpenoid, oleanolic acid, has been improved by chemical modifications. For example, 2-cyano-3,12-diooxooleana-1,9(11)-dien-28-oic acid (CDDO) and related compounds have been developed. See Honda et al., 1997; Honda et al., 1998; Honda et al., 1999; Honda et al., 2000a; Honda et al., 2000b; Honda et al., 2002; Suh et al., 1998; Suh et al., 1999; Place et al., 2003; Liby et al., 2005; and U.S. Pat. Nos. 8,129,429, 7,915,402, 8,124,799, and 7,943,778, all of which are incorporated herein by reference. The methyl ester, bardoxolone methyl (CDDO-Me), has been evaluated in phase II and III clinical trials for the treatment and prevention of diabetic nephropathy and chronic kidney disease. See Pergola et al., 2011, which is incorporated herein by reference.

Synthetic triterpenoid analogs of oleanolic acid have also been shown to be inhibitors of cellular inflammatory processes, such as the induction by IFN-γ of inducible nitric oxide synthase (iNOS) and of COX-2 in mouse macrophages. See Honda et al, (2000a), Honda et al. (2000b), Honda et al. (2002), and U.S. Pat. Nos. 8,129,429, 7,915,402, 8,124,799, and 7,943,778, which are all incorporated herein by reference. Compounds derived from oleanolic acid have been shown to affect the function of multiple protein targets and thereby modulate the activity of several important cellular signaling pathways related to oxidative stress, cell cycle control, and inflammation (e.g., Dinkova-Kostova et al., 2005; Ahmad et al., 2006; Ahmad et al., 2008; Liby et al., 2007a, and U.S. Pat. Nos. 8,129,429, 7,915,402, 8,124,799, and 7,943,778).

Given that the biological activity profiles of known triterpenoid derivatives vary, and in view of the wide variety of diseases that may be treated or prevented with compounds having potent antioxidant and anti-inflammatory effects, and the high degree of unmet medical need represented within this variety of diseases, it is desirable to synthesize new compounds with different biological activity profiles for the treatment or prevention of one or more indications.

SUMMARY OF THE INVENTION

In some aspects of the present invention, there is provided a compound of the formula (also referred to herein as RTA 408, 63415, or PP415):

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is in the form of a pharmaceutically acceptable salt. In some embodiments, the compound is not in the form of a salt.

In another aspect of the present invention, there are provided polymorphic forms of the above compound. In some embodiments, the polymorphic form has an X-ray powder diffraction pattern (CuKα) comprising a halo peak at about 14° 2θ. In some embodiments, the X-ray powder diffraction pattern (CuKα) further comprises a shoulder peak at about 8° 2θ. In some embodiments, the X-ray powder diffraction pattern (CuKα) is substantially as shown in FIG. 59. In some embodiments, the polymorphic form has a T_(g) from about 150° C. to about 155° C., including for example, a T_(g) of about 153° C. or a T_(g) of about 150° C. In some embodiments, the polymorphic form has a differential scanning calorimetry (DSC) curve comprising an endotherm centered from about 150° C. to about 155° C. In some embodiments, the endotherm is centered at about 153° C. In some embodiments, the endotherm is centered at about 150° C. In some embodiments, the differential scanning calorimetry (DSC) curve is substantially as shown in FIG. 62.

In some embodiments, the polymorphic form is a solvate having an X-ray powder diffraction pattern (CuKα) comprising peaks at about 5.6, 7.0, 10.6, 12.7, and 14.6° 2θ. In some embodiments, the X-ray powder diffraction pattern (CuKα) is substantially as shown in FIG. 75, top pattern.

In some embodiments, the polymorphic form is a solvate having an X-ray powder diffraction pattern (CuKα) comprising peaks at about 7.0, 7.8, 8.6, 11.9, 13.9 (double peak), 14.2, and 16.0° 2θ. In some embodiments, the X-ray diffraction pattern (CuKα) is substantially as shown in FIG. 75, second pattern from top.

In some embodiments, the polymorphic form is an acetonitrile hemisolvate having an X-ray powder diffraction pattern (CuKα) comprising peaks at about 7.5, 11.4, 15.6 and 16.6° 2θ. In some embodiments, the X-ray diffraction pattern (CuKα) is substantially as shown in FIG. 75, second pattern from bottom. In some embodiments, the polymorphic form has a T_(g) of about 196° C. In some embodiments, the polymorphic form has a differential scanning calorimetry (DSC) curve comprising an endotherm centered at about 196° C. In some embodiments, the differential scanning calorimetry (DSC) curve is substantially as shown in FIG. 116.

In some embodiments, the polymorphic form is a solvate having an X-ray powder diffraction pattern (CuKα) comprising peaks at about 6.8, 9.3, 9.5, 10.5, 13.6, and 15.6° 2θ. In some embodiments, the X-ray diffraction pattern (CuKα) is substantially as shown in FIG. 75, bottom pattern.

In another aspect of the present invention, there are provided pharmaceutical compositions comprising an active ingredient consisting of the above compound or a polymorphic form thereof (such as, e.g., any one of the polymorphic forms described herein above and below), and a pharmaceutically acceptable carrier. In some embodiments, the pharmaceutical composition is formulated for administration: orally, intraadiposally, intraarterially, intraarticularly, intracranially, intradermally, intralesionally, intramuscularly, intranasally, intraocularly, intrapericardially, intraperitoneally, intrapleurally, intraprostatically, intrarectally, intrathecally, intratracheally, intratumorally, intraumbilically, intravaginally, intravenously, intravesicularlly, intravitreally, liposomally, locally, mucosally, parenterally, rectally, subconjunctival, subcutaneously, sublingually, topically, transbuccally, transdermally, vaginally, in crèmes, in lipid compositions, via a catheter, via a lavage, via continuous infusion, via infusion, via inhalation, via injection, via local delivery, or via localized perfusion. In some embodiments, the pharmaceutical composition is formulated for oral, intraarterial, intravenous, or topical administration. In some embodiments, the pharmaceutical composition is formulated for oral administration.

In some embodiments, the pharmaceutical composition is formulated as a hard or soft capsule, a tablet, a syrup, a suspension, an emulsion, a solution, a solid dispersion, a wafer, or an elixir. In some embodiments, the pharmaceutical composition according to the invention further comprises an agent that enhances solubility and dispersibility. (For example, agents that enhance solubility and dispersibility include, but are not limited to, PEGs, cyclodextrans, and cellulose derivatives.) In some embodiments, the compound or polymorphic form is suspended in sesame oil.

In other embodiments, the pharmaceutical composition is formulated for topical administration. In other embodiments, the pharmaceutical composition is formulated as a lotion, a cream, a gel, an oil, an ointment, a salve, an emulsion, a solution, or a suspension. In some embodiments, the pharmaceutical composition is formulated as a lotion, as a cream, or as a gel. In some embodiments, the amount of the active ingredient is from about 0.01% to about 5% by weight, about 0.01% to about 3% by weight, or 0.01%, 0.1%, 1%, or 3% by weight.

In another aspect of the present invention there are provided methods of treating or preventing a condition associated with inflammation or oxidative stress in a patient in need thereof, comprising administering to the patient a therapeutically effective amount of the pharmaceutical composition as described above or below. The invention likewise relates to the compound N-((4aS,6aR,6bS,8aR,12aS,14aR,14bS)-11-cyano-2,2,6a,6b,9,9,12a-heptamethyl-10,14-dioxo-1,2,3,4,4a,5,6,6a,6b,7,8,8a,9,10,12a,14,14a,14b-octadecahydropicen-4a-yl)-2,2-difluoropropanamide (or RTA 408) or a pharmaceutically acceptable salt thereof, or a polymorphic form of that compound (such as, e.g., any one of the polymorphic forms described herein above or below), or a pharmaceutical composition comprising any of the aforementioned entities and a pharmaceutically acceptable carrier (including, e.g., the pharmaceutical compositions described above), for use in treating or preventing a condition associated with inflammation or oxidative stress. The invention also relates to the use of the aforementioned compound, polymorphic form or pharmaceutical composition for the preparation of a medicament for the treatment or prevention of a condition associated with inflammation or oxidative stress. In some embodiments, the condition is associated with inflammation. In other embodiments, the condition is associated with oxidative stress. In some embodiments, the condition is a skin disease or disorder, sepsis, dermatitis, osteoarthritis, cancer, inflammation, an autoimmune disease, inflammatory bowel disease, a complication from localized or total-body exposure to ionizing radiation, mucositis, acute or chronic organ failure, liver disease, pancreatitis, an eye disorder, a lung disease or diabetes.

The present invention furthermore relates to the compound N-((4aS,6aR,6bS,8aR,12aS,14aR,14bS)-11-cyano-2,2,6a,6b,9,9,12a-heptamethyl-10,14-dioxo-1,2,3,4,4a,5,6,6a,6b,7,8,8a,9,10,12a,14,14a,14b-octadecahydropicen-4a-yl)-2,2-difluoropropanamide (or RTA 408) or a pharmaceutically acceptable salt thereof, or a polymorphic form of that compound (such as, e.g., any one of the polymorphic forms described herein above or below), or a pharmaceutical composition comprising any of the aforementioned entities and a pharmaceutically acceptable carrier (including, e.g., the pharmaceutical compositions described above), for use in treating or preventing a condition selected from a skin disease or disorder, sepsis, dermatitis, osteoarthritis, cancer, inflammation, an autoimmune disease, inflammatory bowel disease, a complication from localized or total-body exposure to ionizing radiation, mucositis, acute or chronic organ failure, liver disease, pancreatitis, an eye disorder, a lung disease, or diabetes. Accordingly, the invention relates to the use of the aforementioned compound, polymorphic form or pharmaceutical composition for the preparation of a medicament for the treatment or prevention of a condition selected from a skin disease or disorder, sepsis, dermatitis, osteoarthritis, cancer, inflammation, an autoimmune disease, inflammatory bowel disease, a complication from localized or total-body exposure to ionizing radiation, mucositis, acute or chronic organ failure, liver disease, pancreatitis, an eye disorder, a lung disease, or diabetes. The invention also relates to a method of treating or preventing a condition selected from a skin disease or disorder, sepsis, dermatitis, osteoarthritis, cancer, inflammation, an autoimmune disease, inflammatory bowel disease, a complication from localized or total-body exposure to ionizing radiation, mucositis, acute or chronic organ failure, liver disease, pancreatitis, an eye disorder, a lung disease, or diabetes in a patient in need thereof, the method comprising administering to the patient a therapeutically effective amount of the aforementioned compound, polymorphic form or pharmaceutical composition. In some embodiments, the condition is a skin disease or disorder such as dermatitis, a thermal or chemical burn, a chronic wound, acne, alopecia, other disorders of the hair follicle, epidermolysis bullosa, sunburn, complications of sunburn, disorders of skin pigmentation, an aging-related skin condition; a post-surgical wound, a scar from a skin injury or burn, psoriasis, a dermatological manifestation of an autoimmune disease or a graft-versus host disease, skin cancer, or a disorder involving hyperproliferation of skin cells. In some embodiments, the skin disease or disorder is dermatitis. In some embodiments, the dermatitis is allergic dermatitis, atopic dermatitis, dermatitis due to chemical exposure, or radiation-induced dermatitis. In other embodiments, the skin disease or disorder is a chronic wound. In some embodiments, the chronic wound is a diabetic ulcer, a pressure sore, or a venous ulcer. In other embodiments, the skin disease or disorder is alopecia. In some embodiments, the alopecia is selected from baldness or drug-induced alopecia. In other embodiments, the skin disease or disorder is a disorder of skin pigmentation. In some embodiments, the disorder of skin pigmentation is vitiligo. In other embodiments, the skin disease or disorder is a disorder involving hyperproliferation of skin cells. In some embodiments, the disorder involving hyperproliferation of skin cells is hyperkeratosis.

In other embodiments, the condition is an autoimmune disease, such as rheumatoid arthritis, lupus, Crohn's disease, or psoriasis. In other embodiments, the condition is a liver disease, such as fatty liver disease or hepatitis.

In other embodiments, the condition is an eye disorder, such as uveitis, macular degeneration, glaucoma, diabetic macular edema, blepharitis, diabetic retinopathy, a disease or disorder of the corneal endothelium, post-surgical inflammation, dry eye, allergic conjunctivitis or a form of conjunctivitis. In some embodiments, the eye disorder is macular degeneration. In some embodiments, the macular degeneration is the dry form. In other embodiments, the macular degeneration is the wet form. In some embodiments, the disease or disorder of the corneal endothelium is Fuchs endothelial corneal dystrophy.

In other embodiments, the condition is a lung disease, such as pulmonary inflammation, pulmonary fibrosis, COPD, asthma, cystic fibrosis, or idiopathic pulmonary fibrosis. In some embodiments, the COPD is induced by cigarette smoke.

In other embodiments, the condition is sepsis. In other embodiments, the condition is mucositis resulting from radiation therapy or chemotherapy. In some embodiments, the mucositis presents orally. In other embodiments, the condition is associated with exposure to radiation. In some embodiments, the radiation exposure leads to dermatitis. In some embodiments, the radiation exposure is acute. In other embodiments, the radiation exposure is fractionated.

In other embodiments, the condition is cancer. In some embodiments, the cancer is a carcinoma, sarcoma, lymphoma, leukemia, melanoma, mesothelioma, multiple myeloma, or seminoma. In other embodiments, the cancer is of the bladder, blood, bone, brain, breast, central nervous system, cervix, colon, endometrium, esophagus, gall bladder, genitalia, genitourinary tract, head, kidney, larynx, liver, lung, muscle tissue, neck, oral or nasal mucosa, ovary, pancreas, prostate, skin, spleen, small intestine, large intestine, stomach, testicle, or thyroid.

In some embodiments, the pharmaceutical composition is administered before or immediately after a subject is treated with a radiation therapy or a chemotherapy wherein the chemotherapy does not comprise RTA 408 or its polymorphic forms. In some embodiments, the pharmaceutical composition is administered both before and after the subject is treated with radiation therapy, chemotherapy or both. In some embodiments, the treatment reduces a side effect of the radiation therapy or the chemotherapy. In some embodiments, the side effect is mucositis and dermatitis. In some embodiments, the treatment enhances the efficacy of the radiation therapy or the chemotherapy. In some embodiments, the chemotherapy comprises administering to the patient a therapeutically effective amount of 5-fluorouracil or docetaxel.

Additional combination treatment therapy is also contemplated by the present disclosure. For example, in some embodiments, the methods of treating cancer in a subject, comprising administering to the subject a pharmaceutically effective amount of a compound of the present disclosure, the methods may further comprise one or more treatments selected from the group consisting of administering a pharmaceutically effective amount of a second drug, radiotherapy, immunotherapy, gene therapy, and surgery. In some embodiments, the methods may further comprise (1) contacting a tumor cell with the compound prior to contacting the tumor cell with the second drug, (2) contacting a tumor cell with the second drug prior to contacting the tumor cell with the compound, or (3) contacting a tumor cell with the compound and the second drug at the same time. The second drug may, in certain embodiments, be an antibiotic, anti-inflammatory, anti-neoplastic, anti-proliferative, anti-viral, immunomodulatory, or immunosuppressive. In other embodiments, the second drug may be an alkylating agent, androgen receptor modulator, cytoskeletal disruptor, estrogen receptor modulator, histone-deacetylase inhibitor, HMG-CoA reductase inhibitor, prenyl-protein transferase inhibitor, retinoid receptor modulator, topoisomerase inhibitor, or tyrosine kinase inhibitor. In certain embodiments, the second drug is 5-azacitidine, 5-fluorouracil, 9-cis-retinoic acid, actinomycin D, alitretinoin, all-trans-retinoic acid, annamycin, axitinib, belinostat, bevacizumab, bexarotene, bosutinib, busulfan, capecitabine, carboplatin, carmustine, CD437, cediranib, cetuximab, chlorambucil, cisplatin, cyclophosphamide, cytarabine, dacarbazine, dasatinib, daunorubicin, decitabine, docetaxel, dolastatin-10, doxifluridine, doxorubicin, doxorubicin, epirubicin, erlotinib, etoposide, gefitinib, gemcitabine, gemtuzumab ozogamicin, hexamethylmelamine, idarubicin, ifosfamide, imatinib, irinotecan, isotretinoin, ixabepilone, lapatinib, LBH589, lomustine, mechlorethamine, melphalan, mercaptopurine, methotrexate, mitomycin, mitoxantrone, MS-275, neratinib, nilotinib, nitrosourea, oxaliplatin, paclitaxel, plicamycin, procarbazine, semaxanib, semustine, sodium butyrate, sodium phenylacetate, streptozotocin, suberoylanilide hydroxamic acid, sunitinib, tamoxifen, teniposide, thiopeta, tioguanine, topotecan, TRAIL, trastuzumab, tretinoin, trichostatin A, valproic acid, valrubicin, vandetanib, vinblastine, vincristine, vindesine, or vinorelbine.

Methods of treating or preventing a disease with an inflammatory component in a subject, comprising administering to the subject a pharmaceutically effective amount of a compound of the present disclosure are also contemplated. In some embodiments, the disease may be, for example, lupus or rheumatoid arthritis. In other embodiments, the disease may be an inflammatory bowel disease, such as Crohn's disease or ulcerative colitis. In other embodiments, the disease with an inflammatory component may be a cardiovascular disease. In other embodiments, the disease with an inflammatory component may be diabetes, such as type 1 or type 2 diabetes. In other embodiments, RTA 408, its polymorphs, and pharmaceutical compositions may also be used to treat complications associated with diabetes. Such complications are well-known to a person of skill in the art and include but are not limited to, for example, obesity, hypertension, atherosclerosis, coronary heart disease, stroke, peripheral vascular disease, hypertension, nephropathy, neuropathy, myonecrosis, retinopathy and metabolic syndrome (syndrome X). In other embodiments, the disease with an inflammatory component may be a skin disease, such as psoriasis, acne, or atopic dermatitis. Administration of RTA 408, its polymorphs, and pharmaceutical compositions in treatment methods of such skin diseases may be but are not limited to, for example, topical or oral.

In other embodiments, the disease with an inflammatory component may be metabolic syndrome (syndrome X). A patient having this syndrome is characterized as having three or more symptoms selected from the following group of five symptoms: (1) abdominal obesity; (2) hypertriglyceridemia; (3) low high-density lipoprotein cholesterol (HDL); (4) high blood pressure; and (5) elevated fasting glucose, which may be in the range characteristic of Type 2 diabetes if the patient is also diabetic. Each of these symptoms is defined in the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III, or ATP III), National Institutes of Health, 2001, NIH Publication No. 01-3670, which is incorporated herein by reference. Patients with metabolic syndrome, whether or not they have or develop overt diabetes mellitus, have an increased risk of developing the macrovascular and microvascular complications that are listed above that occur with type 2 diabetes, such as atherosclerosis and coronary heart disease.

Another general method of the present disclosure entails a method of treating or preventing a cardiovascular disease in a subject, comprising administering to the subject a pharmaceutically effective amount of a compound of the present disclosure. In some embodiments, the cardiovascular disease may be but not limited to, for example, atherosclerosis, cardiomyopathy, congenital heart disease, congestive heart failure, myocarditis, rheumatic heart disease, valve disease, coronary artery disease, endocarditis, or myocardial infarction. Combination therapy is also contemplated for methods of treating or preventing a cardiovascular disease in a subject. For example, such methods may further comprise administering a pharmaceutically effective amount of one or more cardiovascular drugs. The cardiovascular drug may be but not limited to, for example, a cholesterol lowering drug, an anti-hyperlipidemic, a calcium channel blocker, an anti-hypertensive, or an HMG-CoA reductase inhibitor. In some embodiments, non-limiting examples of cardiovascular drugs include amlodipine, aspirin, ezetimibe, felodipine, lacidipine, lercanidipine, nicardipine, nifedipine, nimodipine, nisoldipine or nitrendipine. In other embodiments, other non-limiting examples of cardiovascular drugs include atenolol, bucindolol, carvedilol, clonidine, doxazosin, indoramin, labetalol, methyldopa, metoprolol, nadolol, oxprenolol, phenoxybenzamine, phentolamine, pindolol, prazosin, propranolol, terazosin, timolol or tolazoline. In other embodiments, the cardiovascular drug may be, for example, a statin, such as atorvastatin, cerivastatin, fluvastatin, lovastatin, mevastatin, pitavastatin, pravastatin, rosuvastatin or simvastatin.

Methods of treating or preventing a neurodegenerative disease in a subject, comprising administering to the subject a pharmaceutically effective amount of a compound of the present disclosure are also contemplated. In some embodiments, the neurodegenerative disease may be selected, for example, from the group consisting of Parkinson's disease, Alzheimer's disease, multiple sclerosis (MS), Huntington's disease and amyotrophic lateral sclerosis. In particular embodiments, the neurodegenerative disease is Alzheimer's disease. In particular embodiments, the neurodegenerative disease is MS, such as primary progressive, relapsing-remitting secondary progressive or progressive relapsing MS. In some embodiments, the subject may be, for example, a primate. In some embodiments, the subject may be a human.

In particular embodiments of methods of treating or preventing a neurodegenerative disease in a subject, comprising administering to the subject a pharmaceutically effective amount of a compound of the present disclosure, the treatment suppresses the demyelination of neurons in the subject's brain or spinal cord. In certain embodiments, the treatment suppresses inflammatory demyelination. In certain embodiments, the treatment suppresses the transection of neuron axons in the subject's brain or spinal cord. In certain embodiments, the treatment suppresses the transection of neurites in the subject's brain or spinal cord. In certain embodiments, the treatment suppresses neuronal apoptosis in the subject's brain or spinal cord. In certain embodiments, the treatment stimulates the remyelination of neuron axons in the subject's brain or spinal cord. In certain embodiments, the treatment restores lost function after an MS attack. In certain embodiments, the treatment prevents a new MS attack. In certain embodiments, the treatment prevents a disability resulting from an MS attack.

One general aspect of the present disclosure contemplates a method of treating or preventing a disorder characterized by overexpression of iNOS genes in a subject, comprising administering to the subject a pharmaceutically effective amount of RTA 408, polymorphic forms, or a pharmaceutical composition of the present disclosure.

Another general aspect of the present disclosure contemplates a method of inhibiting IFN-γ-induced nitric oxide production in cells of a subject, comprising administering to said subject a pharmaceutically effective amount of RTA 408, polymorphic forms, or a pharmaceutical composition of the present disclosure.

Yet another general method of the present disclosure contemplates a method of treating or preventing a disorder characterized by overexpression of COX-2 genes in a subject, comprising administering to the subject a pharmaceutically effective amount of RTA 408, polymorphic forms, or a pharmaceutical composition of the present disclosure.

Methods of treating renal/kidney disease (RKD) in a subject, comprising administering to the subject a pharmaceutically effective amount of a compound of the present disclosure are also contemplated. See U.S. Pat. No. 8,129,429, which is incorporated by reference herein. The RKD may result from, for example, a toxic insult. The toxic insult may result from but not limited to, for example, an imaging agent or a drug. The drug may be a chemotherapeutic, for example. The RKD may result from ischemia/reperfusion injury, in certain embodiments. In certain embodiments, the RKD results from diabetes or hypertension. In some embodiments, the RKD may result from an autoimmune disease. The RKD may be further defined as chronic RKD or acute RKD.

In certain methods of treating renal/kidney disease (RKD) in a subject, comprising administering to the subject a pharmaceutically effective amount of a compound of the present disclosure, the subject has undergone or is undergoing dialysis. In certain embodiments, the subject has undergone or is a candidate to undergo kidney transplant. The subject may be a primate. The primate may be a human. The subject in this or any other method may be, for example, a cow, horse, dog, cat, pig, mouse, rat or guinea pig.

Also contemplated by the present disclosure is a method for improving glomerular filtration rate or creatinine clearance in a subject, comprising administering to the subject a pharmaceutically effective amount of RTA 408, polymorphic forms, or a pharmaceutical composition of the present disclosure.

In some embodiments, the pharmaceutical composition is administered in a single dose per day. In other embodiments, the pharmaceutical composition is administered in more than one dose per day. In some embodiments, the pharmaceutical composition is administered in a pharmaceutically effective amount.

In some embodiments, the dose is from about 1 mg/kg to about 2000 mg/kg. In other embodiments, the dose is from about 3 mg/kg to about 100 mg/kg. In other embodiments, the dose is about 3, 10, 30, or 100 mg/kg.

In other embodiments, the pharmaceutical composition is administered topically. In some embodiments, the topical administration is administered to the skin. In other embodiments, the topical administration is administered to the eye.

In other embodiments, the pharmaceutical composition is administered orally. In other embodiments, the pharmaceutical composition is administered intraocularly.

Other objects, features and advantages of the present disclosure will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. Note that simply because a particular compound is ascribed to one particular generic formula does not mean that it cannot also belong to another generic formula.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present disclosure. One or more German words can be found in the drawings, including “Masseänderung” and “temperatur”, which mean “change in mass” and “temperature”, respectively. The invention may be better understood by reference to one of these drawings in combination with the detailed description of specific embodiments presented herein.

FIG. 1—Effect of RTA 408 on IFNγ-induced nitric oxide production and cell viability in RAW264.7 cells.

FIGS. 2 a & b—Effect of RTA 408 on antioxidant response element (ARE) activation: (a) NQO1-ARE luciferase activity; (b) GSTA2-ARE luciferase activity.

FIGS. 3 a-f—Relative Nrf2 GST ARE fold increase after cellular treatment with (a) RTA 402; (b) 63415 (RTA 408); (c) 63170; (d) 63171; (e) 63179; and (f) 63189. The graph also show the viability of the cells as assayed using the WST1 cell proliferation reagent and measuring the absorbance after 1 hour. All drugs were administered in DMSO and cells were grown at 10,000 cells/well in 384-well plates in DMEM low glucose supplemented with 10% FBS, 1% Penicillin Streptomycin, and 0.8 mg/mL Geneticin.

FIGS. 4 a-d—Effect of RTA 408 on Nrf2 target gene expression in HFL1 lung fibroblasts. (a) NQO1; (b) HMOX1; (c) GCLM; (d) TXNRD1.

FIGS. 5 a-d—Effect of RTA 408 on Nrf2 target gene expression in BEAS-2B bronchial epithelial cells. (a) NQO1; (b) HMOX1; (c) GCLM; (d) TXNRD1.

FIGS. 6 a & b—Effect of RTA 408 on Nrf2 target protein levels. (a) SH-SY5Y cells; (b) BV2 cells.

FIG. 7—Effect of RTA 408 on NQO1 enzymatic activity in RAW264.7 cells.

FIG. 8—Effect of RTA 408 on total glutathione levels in the AML-12 hepatocyte cell line.

FIG. 9—Effect of RTA 408 on WST-1 absorbance as a marker of NADPH.

FIGS. 10 a-d—Effect of RTA 408 on expression of genes involved in NADPH synthesis. (a) H6PD; (b) PGD; (c) TKT; (d) ME1.

FIGS. 11 a & b—(a) Effect of RTA 408 on TNF-α-induced activation of an NF-κB luciferase reporter in the mouse NIH3T3 cell line with WST1 viability and WST1/2 viability overlaid. (b) TNF-α-induced activation of an NF-κB luciferase reporter in the mouse NIH3T3 cell line. The graph shows relative fold change as a function of log change in RTA 408 concentration.

FIG. 12—Effect of RTA 408 on TNF-α-induced activation of a NF-κB luciferase reporter construct.

FIGS. 13 a & b—(a) Effect of RTA 408 on TNF-α-induced activation of an NF-κB luciferase reporter in the human A549 cell line with WST1 viability and WST1/2 viability overlaid. (b) TNF-α-induced activation of an NF-κB luciferase reporter in the human A549 cell line. The graph shows relative fold change as a function of log change in RTA 408 concentration.

FIG. 14—Effect of RTA 408 on TNF-α-induced phosphorylation of IκBα.

FIGS. 15 a-d—Effect of RTA 408 on transaminase gene expression: (a) ALT1 (GPT1); (b) ALT2 (GPT2); (c) AST1 (GOT1); (d) AST1 (GOT2). Asterisks indicate a statistically-significant difference from the control group (*P<0.05; **P<0.01).

FIG. 16—Effect of RTA 408 on pyruvate levels in cultured muscle cells (*P<0.05).

FIG. 17—Effect of 63415 in a model of pulmonary LPS-mediated inflammation (% change in pro-inflammatory cytokines relative to LPS treatment). Compound 63415 was administered QD×3 at Time 0, 24, and 48 h followed by LPS one h after the last dose of 63415 in female BALB/c mice. Animals were sacrificed 20 h after LPS administration. BALF was examined for pro-inflammatory cytokine expression. Compound 63415 reduced pro-inflammatory cytokines in a dose-dependent manner, with peak reductions ranging from 50%-80% in TNF-α, IL-6, and IL-12.

FIGS. 18 a & b—Effect of RTA 408 on LPS-induced pulmonary inflammation in mice. (a) inflammatory cytokines; (b) Nrf2 targets. RTA 408 was administered to female BALB/c mice (n=10) QD×6 at Time 0, 24, 48, 72, 96, and 120 h followed by LPS at 121 h with animals sacrificed at 141 h. Pro-inflammatory cytokine protein expression assayed in BALF. Nrf2 biomarkers assayed in lung. Asterisks indicate a statistically significant difference from the saline control group (*P<0.05; **P<0.01; ***P<0.001).

FIGS. 19 a & b—Effect of 63415 on BALF infiltrates in bleomycin-induced pulmonary inflammation: (a) BAL fluid cell count; (b) body weight. Compound 63415 was administered QD×39 on Days −10 to 28 in C57BL/6 mice. Bleomycin was given on Day 0. Daily weights were measured. BALF cell counts were obtained at sacrifice. A notable reduction in inflammatory infiltrate was observed. No significant improvements in chronic inflammation score, interstitial fibrosis, or number of fibrotic foci were observed.

FIGS. 20 a & b—Effect of RTA 408 on bleomycin-induced pulmonary fibrosis in rats: (a) PMN; (b) Hydroxyproline. Asterisks indicate a statistically significant difference from the bleomycin control group (*P<0.05).

FIG. 21—Effect of RTA 408 on Nrf2 target enzymes in lungs from rats with bleomycin-induced pulmonary fibrosis. Asterisks indicate a statistically significant difference from the saline control group (*P<0.05; **P<0.01; ***P<0.001).

FIGS. 22 a-e—Effect of RTA 408 on cigarette smoke-induced COPD in mice. (a) KC; (b) IL-6; (c) TNF-α; (d) IFN-γ; (e) RANTES. RTA 408 (63415) was tested at dose levels of 3 mg/kg (low), 10 mg/kg (mid), and 30 mg/kg (high). An AIM analog (63355) was tested in the same study for comparison. Asterisks indicate a statistically significant difference form the CS control group.

FIG. 23—Effect of RTA 408 on Nrf2 target enzymes in lungs from mice with cigarette smoke-induced COPD. Asterisks indicate a statistically significant difference from the saline control group (*P<0.05; **P<0.01; ***P<0.001). Daggers represent a statistically significant difference from mice expose to cigarette smoke and administered vehicle (†P<0.05).

FIGS. 24 a-d—Effects of 63415 (RTA 408) on body weight in a BALB/c mouse model of sepsis. LPS was administered to all animals on Day 0. (a) Body Weight: 63415 (RTA 408); (b) Body Weight: RTA 405; (c) Systemic LPS: % Survival: 63415 (RTA 408); (d) Systemic LPS: % Survival: RTA 405. Both RTA 405 and 63415 (RTA 408) were administered QD×5 on Days −2 to 2. 63415 (RTA 408) improved survival. Body weight as a function of time in 63415-treated BALB/c mice serves as a model for sepsis.

FIG. 25—Effect of 63415 in a model of radiation-induced oral mucositis. RTA 405 or 63415 (RTA 408) was administered BID×20 on Days −5 to −1 and Days 1 to 15 to male Syrian Golden Hamsters. Radiation occurred on Day 0. Mucositis scores range from 0 to 5 based on clinical manifestations (0: completely healthy; 1-2: light to severe erythema; 3-5: varying degrees of ulceration). 63415 improved mucositis at 30 mg/kg and 100 mg/kg with up to a 36% reduction in ulceration.

FIG. 26—Effect of 63415 on Nrf2 target gene induction in a 14-day mouse toxicity study in C57BL/6 mice. mRNAs of Nrf2 target genes were assessed in livers of mice treated PO QD×14. Substantial increases in mRNA expression for multiple Nrf2 target genes were observed and were consistent with tissue exposure.

FIGS. 27 a & b—Effect of 63415 on Nrf2 target gene induction in rat livers: (a) Target genes; (b) Negative regulators. mRNAs of Nrf2 target genes were assessed in livers of rats treated PO QD×14.

FIGS. 28 a & b—Effect of 63415 on Nrf2 target genes in monkey tissues: (a) Liver; (b) Lung mRNAs of Nrf2 target genes were assessed in monkeys treated PO QD×14 using Panomics QuantiGene® 2.0 Plex technology.

FIGS. 29 a & b—Effect of 63415 on Nrf2 target enzyme activity in mouse liver: (a) NQO1 activity; (b) GST activity. Nrf2 target enzyme activity was assessed in livers of mice treated PO QD×14. NQO1 and GST enzyme activities were induced in a dose-dependent manner.

FIGS. 30 a & b—Effect of 63415 on Nrf2 target enzyme activity in rat liver: (a) NQO1 activity; (b) GST activity. Nrf2 target enzyme activity was assessed in livers of rats treated PO QD×14. NQO1 and GST enzyme activities were induced in a dose dependent manner.

FIGS. 31 a & b—Effects of 63415 on Nrf2 target enzyme activity induction in various tissues of cynomolgus monkeys: (a) NQO1 activity; (b) GSR activity.

FIGS. 32 a & b—RTA 408 concentration in mouse liver, lung, and brain, and NQO1 activity in mouse liver after 14 days of daily oral administration. (a) Tissue distribution of RTA 408 in mice after 14 days of daily oral administration. Data represent the mean±SD of RTA 408 concentrations in tissue collected 4 h after the final dose of the study. Numbers above the error bars are representative of the mean. (b) Correlation of mouse liver RTA 408 content with NQO1 enzyme activity. Individual mouse liver RTA 408 liver content was plotted against individual enzyme activity from this report.

FIGS. 33 a & b—RTA 408 concentration in rat plasma, liver, lung, and brain, and NQO1 activity in rat liver after 14 days of daily oral administration. (a) Tissue distribution of RTA 408 in rats after 14 days of daily oral administration. Data represent the mean±SD of RTA 408 concentrations in tissue collected 4 h after the final dose of the study. Numbers above the error bars are representative of the mean. *Two values were excluded from the mean calculation due to being outliers, defined as values causing the set of data to fail the Shapiro-Wilk normality test. (b) Correlation of rat liver RTA 408 content with NQO1 enzyme activity. Individual rat liver RTA 408 content was plotted against individual enzyme activity from this report. The tissues from the 100 mg/kg RTA 408 dose group were collected on Day 6, and the observed toxicities in this group precluded liver NQO1 enzyme activity evaluations.

FIGS. 34 a & b—Effect of 63415 treatment on Nrf2 activation in monkey PBMC: (a) PBMC NQO1 vs. Plasma Concentration; (b) Lung NQO1 vs. PBMC NQO1.

FIG. 35—Summary of 63415 14-day monkey toxicity study. All doses were well-tolerated without adverse clinical signs. Clinical chemistry data suggested no obvious toxicity.

FIG. 36—Effect of dosing time on plasma concentration of RTA 408 after topical ocular and oral administration. The plasma concentration of RTA 408 was also measured after 5 days of daily topical ocular administration of RTA 408 and determined to remain relatively consistent from the measurements taken after the first day.

FIGS. 37 a & b—Correlation of exposure to RTA 408 in monkey plasma with NQO1 and SRXN1 mRNA expression in PBMCs: (a) NQO1; (b) SRXN1.

FIG. 38—Concentration of RTA 408 in various tissues or fluids within the eye as a function of time after 5 days of topical ocular dosing. RTA 408 concentration in plasma was also measured after topical ocular administration.

FIG. 39—Effect of RTA 408 on the incidence of grade 3 dermatitis caused by acute radiation exposure for different concentrations of topically administered RTA 408.

FIG. 40—Effect of RTA 408 on the incidence of grade 2 dermatitis caused by acute radiation exposure over a 30 day treatment course for different concentrations of topically administered RTA 408.

FIG. 41—Effect of RTA 408 on the incidence of grade 2 dermatitis caused by acute radiation exposure over a 28 day treatment course for different concentrations of orally administered RTA 408.

FIGS. 42 a & b—(a) Area under the curve analysis of clinical score of the dermatitis as a function of time for each of the different control groups including all of the animals used in the test. (b) Area under the curve analysis of the clinical score of the dermatitis as a function of the duration of that score for each of the different control groups including only animals that completed the entire 30 days in the trial.

FIG. 43—Average 1^(st) blind score of acute radiation dermatitis as a function of time for untreated, untreated with no radiation exposure, vehicle only and three oral amounts of RTA 408 at 3, 10, and 30 mg/kg. The dermatitis score was based upon a scale that 0 was completely healthy, 1-2 exhibited mild to moderate erythema with minimal to slight desquamation, 3-4 exhibited moderate to severe erythema and desquamation, and 5 exhibited a frank ulcer.

FIG. 44—Mean score of the acute radiation dermatitis as a function of time for untreated, untreated with no radiation exposure, vehicle only, and three oral amounts of RTA 408 at 3, 10, and 30 mg/kg measured every other day from day 4 to day 30. The dermatitis score was based upon a scale that 0 was completely healthy, 1-2 exhibited mild to moderate erythema with minimal to slight desquamation, 3-4 exhibited moderate to severe erythema and desquamation, and 5 exhibited a frank ulcer.

FIG. 45—Mean score of the acute radiation dermatitis as a function of time for untreated, untreated with no radiation exposure, vehicle only, and three topical amounts of RTA 408 at 0.01%, 0.1%, and 1% measured every other day from day 4 to day 30. The dermatitis score was based upon a scale that 0 was completely healthy, 1-2 exhibited mild to moderate erythema with minimal to slight desquamation, 3-4 exhibited moderate to severe erythema and desquamation, and 5 exhibited a frank ulcer.

FIG. 46—Clinical scores of fractional radiation dermatitis plotted versus time and changes in dermatitis score for each testing group. The dermatitis score was based upon a scale that 0 was completely healthy, 1-2 exhibited mild to moderate erythema with minimal to slight desquamation, 3-4 exhibited moderate to severe erythema and desquamation, and 5 exhibited a frank ulcer.

FIG. 47—Graph of the AUC analysis showing the dermatitis score (severity×days) for each of the testing groups over the entire observation period. The dermatitis scores were assessed every two days from day 4 to day 30 of the study.

FIGS. 48 a & b—(a) Graph of the absorbance at 595 nm for treated prostate cancer cell line LNCaP showing relative cytotoxic effect on cells treated with a chemotherapeutic agent and RTA 408 versus RTA 408 alone. (b) Graph of the absorbance at 595 nm for treated prostate cancer cell line DU-145 showing relative cytotoxic effect on cells treated with a chemotherapeutic agent and RTA 408 versus RTA 408 alone.

FIG. 49—Black and white versions of color photographs of imaged mice showing the luciferase activity of tumors for three mice: a control animal with no treatment, an animal subjected only to ionizing radiation (single dose, 18 Gy), and an animal given both ionizing radiation (single dose, 18 Gy, day 0) and RTA 408 (17.5 mg/kg i.p., once daily on days −3 to −1, then single doses on days 1, 3, and 5). The colors indicated by the arrows are indicative of intensity with the intensities being represented by red, yellow, green, and blue in order from highest to lowest intensity.

FIG. 50—Reduction of aqueous humor protein concentrations for different formulations of RTA 408 (dark bars) compared to literature values for MaxiDex® (0.1% dexamethasone) and mapracorat (light bars) after induction of paracentesis.

FIG. 51—Dose-dependent suppression of NO in vivo by 63415. CD-1 mice (n=6) were dosed with DMSO or AIM by oral gavage. LPS (5 mg/kg) was administered 24 h later. Twenty-four hours after LPS administration, whole blood was collected for NO assay. NO inhibition was determined by Griess Reaction from reduced, de-proteinated plasma.

FIG. 52—Extensive distribution of 63415 (RTA 408) into mouse tissues. Mice were dosed PO QD×3 with either 25 mg/kg 63415 (RTA 408) or 25 mg/kg RTA 405. Blood (plasma and whole blood) and tissues (brain, liver, lung, and kidney) were collected 6 h after the last dose. Semi-quantitative analysis of drug content was performed. Notable levels were observed in the CNS.

FIG. 53—NQO1 activity induction in mouse liver, lung, and kidney by 63415. Mice were dosed PO QD×3 with 25 mg/kg. Tissues were collected 6 h after the last dose, and analysis of NQO1 activity was performed. Meaningful activation of NQO1 was observed in multiple tissues.

FIG. 54—Summary of 63415 14-day mouse toxicity study. C57BL/6 mice were dosed PO QD×14. Endpoints included survival, weight, and clinical chemistries. All animals survived to day 14. No significant weight changes occurred compared to the vehicle group, and there was no evidence of toxicity at any dose based on clinical chemistries.

FIG. 55—Tissue distribution of 63415 from 14-day mouse toxicity study in C57BL/6 mice. Brain, lung, and liver samples were collected 4 h after final dose and quantified for 63415 content using sensitive LC/MS/MS method. Exposures at 10 and 100 mg/kg in lung exceeded the in vitro IC₅₀ for NO induction by 55- and 1138-fold, respectively. Exposure at 10 and 100 mg/kg in brain exceeded the in vitro IC₅₀ for NO induction by 29- and 541-fold, respectively.

FIG. 56—Tissue distribution of 63415 in Sprague Dawley rats. Tissues were collected four hours after final dosing on Day 14 or Day 6 (100 mg/kg), extracted, and quantified for 63415 content using a sensitive LC/MS/MS method. Compound 63415 distributes well into target tissues. Exposures at 10 mg/kg in lung and brain exceed the in vitro IC₅₀ for NO inhibition by 294- and 240-fold, respectively.

FIG. 57—Target tissue distribution of compound 63415 in cynomolgus monkeys. Tissues were collected four hours after final dosing on Day 14. Compound 63415 content was extracted and quantified using a sensitive LC/MS/MS method.

FIG. 58—FT-Raman spectrum (3400-50 cm⁻¹) of the sample PP415-P1, which corresponds to the amorphous form (Class 1).

FIG. 59—PXRD (1.5-55.5° 2θ) pattern of the sample PP415-P1, which corresponds to the amorphous form (Class 1).

FIG. 60—TG-FTIR thermogram (25-350° C.) of the sample PP415-P1, which corresponds to the amorphous form (Class 1).

FIG. 61—¹H-NMR spectrum in DMSO-d₆ of the sample PP415-P1, which corresponds to the amorphous form (Class 1).

FIG. 62—DSC thermogram of the sample PP415-P1, which corresponds to the amorphous form (Class 1).

FIG. 63—DVS isotherm of the sample PP415-P1, which corresponds to the amorphous form (Class 1).

FIG. 64—FT-Raman spectrum of the sample PP415-P1, which corresponds to the amorphous form (Class 1), after DVS measurement (top) is unchanged compared to the material before the DVS measurement (bottom). The spectra have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 65—PXRD pattern of the sample PP415-P1, which corresponds to the amorphous form (Class 1), after DVS measurement (top) is unchanged compared to the material before the DVS measurement (bottom). The patterns have not been scaled but are offset in the y-direction for the purpose of comparison.

FIG. 66—PXRD pattern of the sample PP415-P40 (top) corresponds to the pattern of the solvate form (Class 2) (bottom, sample PP415-P19). The patterns have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 67—PXRD patterns of the stability samples PP415-P2a (top), PP415-P3a (2^(nd) from top), PP415-P4a (middle), and PP415-P5a (2^(nd) from bottom), which corresponds to the amorphous form (Class 1), after one week show no differences compared to the starting material at time point t₀ (bottom, sample PP415-P1). The patterns are not scaled but are offset in the y-direction for the purpose of comparison.

FIG. 68—PXRD patterns of the stability samples PP415-P2b (top), PP415-P3b (2^(nd) from stop), PP415-P4b (middle), and PP415-P5b (2^(nd) from bottom), which corresponds to the amorphous form (Class 1), after two weeks show no differences compared to the starting material at time point t₀ (bottom, sample PP415-P1). The patterns are not scaled but are offset in the y-direction for the purpose of comparison.

FIG. 69—PXRD patterns of the stability samples PP415-P2c (top), PP415-P3c (2^(nd) from top), PP415-P4c (middle), and PP415-P5c (2^(nd) from bottom), which corresponds to the amorphous form (Class 1), after four weeks show no differences compared to the starting material at time point t0 (bottom, sample PP415-P1). The patterns are not scaled but are offset in the y-direction for the purpose of comparison.

FIG. 70—FT-Raman spectra (2400-50 cm⁻¹) of samples of the solvate form (Class 2) (PP415-P7: top; PP415-P8: 2^(nd) from top; PP415-P9: 3^(rd) from top; PP415-P10: 4^(th) from top; PP415-P11: middle; PP415-P15: 4^(th) from bottom; PP415-P17: 3^(rd) from bottom; PP415-P21: 2^(nd) from bottom; PP415-P24: bottom). The spectra have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 71—FT-Raman spectrum (1750-1000 cm⁻¹) of the solvate form (Class 2) (PP415-P7: top) clearly differs from the spectrum of the amorphous form (Class 1) (PP415-P1: bottom). The spectra have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 72—FT-Raman spectra (1750-1000 cm⁻¹) of class 2 (sample PP415-P19: top), class 3 (sample PP415-P6: 2^(nd) from top), class 4 (sample PP415-P13: 2^(nd) from bottom), and class 5 (sample PP415-P14: bottom) differ significantly from each other. The spectra have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 73—PXRD patterns (2-32° 2θ) of samples of the solvate form (Class 2) (PP415-P7: top; PP415-P8: 2^(nd) from top; PP415-P10: 3^(rd) from top; PP415-P15: 4^(th) from top; PP415-P17: middle; PP415-P18: 4^(th) from bottom; PP415-P19: 3^(rd) from bottom; PP415-P21: 2^(nd) from bottom; PP415-P24: bottom). The patterns have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 74—PXRD patterns (11-21° 2θ) of some samples of the solvate form (Class 2) (PP415-P7: top; PP415-P8: 2^(nd) from top; PP415-P10: middle; PP415-P21: 2^(nd) from bottom; PP415-P24: bottom). The patterns have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 75—PXRD patterns (2-32° 2θ) of class 2 (sample PP415-P19: top), class 3 (sample PP415-P6: 2^(nd) from top), class 4 (sample PP415-P13: 2^(nd) from bottom), and class 5 (sample PP415-P14: bottom) are distinctly different. The patterns have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 76—TG-FTIR thermogram of the sample PP415-P7, which corresponds to a solvate form (Class 2).

FIG. 77—TG-FTIR thermogram of the sample PP415-P21, which corresponds to a solvate form (Class 2).

FIG. 78—TG-FTIR thermogram of the sample PP415-P24, which corresponds to a solvate form (Class 2).

FIG. 79—TG-FTIR thermogram of the sample PP415-P29, which corresponds to a solvate form (Class 2).

FIG. 80—TG-FTIR thermogram of the sample PP415-P47, which corresponds to a solvate form (Class 2).

FIG. 81—TG-FTIR thermogram of the sample PP415-P48, which corresponds to a solvate form (Class 2).

FIG. 82—FT-Raman spectra (1800-700 cm⁻¹) of the solvate form (Class 2) (bottom, sample PP415-P7) and of the dried solvate form (Class 2) (top, sample PP415-P30) are similar and show only small differences which can hardly be distinguished within the graph. The spectra are scaled for the purpose of comparison.

FIG. 83—PXRD pattern of the dried solvate form (Class 2), sample PP415-P30 (top) in comparison to the pattern of the solvate form (Class 2), sample PP415-P7 (bottom). The patterns are not scaled but are offset in the y-direction for the purpose of comparison.

FIG. 84—TG-FTIR thermogram of the dried sample PP415-P30, which corresponds to a solvate form (Class 2).

FIG. 85—FT-Raman spectrum of the dried sample PP415-P18 (light grey) is identical to the spectrum of the original sample PP415-P15 (dark grey) are similar and show only small differences which can hardly be distinguished within the graph. The spectra have been scaled for the purpose of comparison.

FIG. 86—PXRD pattern of the dried sample PP415-P18 (top) shows small differences from the pattern of the original sample PP415-P15 (bottom), although both solvate forms (Class 2). The patterns have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 87—TG-FTIR thermogram of the sample PP415-P18, which corresponds to a solvate form (Class 2).

FIG. 88—FT-Raman spectrum of the sample PP415-P17 (top) is nearly identical to the spectra of the dried samples PP415-P19 (middle) and PP415-P32 (bottom) and show only small differences which can hardly be distinguished within the graph. The spectra have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 89—PXRD pattern of the dried sample PP415-P19 (middle) is different from the pattern of the original sample PP415-P17 (top) but still corresponds to class 2 form. The pattern of the further dried sample PP415-P32 (bottom) shows broader peaks with a lower S/N ratio. The material is less crystalline, but still corresponds to class 2 form. The patterns have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 90—TG-FTIR thermogram of the sample PP415-P19, which corresponds to a solvate form (Class 2).

FIG. 91—TG-FTIR thermogram of the sample PP415-P32A, which corresponds to a solvate form (Class 2).

FIG. 92—FT-Raman spectrum of the sample PP415-P21 (top) is identical to the spectra of the dried samples PP415-P28 (middle) and PP415-P34 (bottom). The spectra have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 93—PXRD patterns of the dried samples PP415-P28 (middle) and PP415-P34 (bottom) show broader peaks with a lower S/N ratio, indicating a lower crystallinity of the samples compared to the pattern of the original sample PP415-P21 (top). The patterns are somewhat different but still correspond to class 2 form. They have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 94—TG-FTIR thermogram of the dried sample PP415-P28, which corresponds to a solvate form (Class 2).

FIG. 95—TG-FTIR thermogram of the dried sample PP415-P34, which corresponds to a solvate form (Class 2).

FIG. 96—FT-Raman spectra (2400-50 cm⁻¹) of the samples of the solvate form (Class 3) (PP415-P6: top; PP415-P12: middle; PP415-P20: bottom). The spectra have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 97—FT-Raman spectra (1750-1000 cm⁻¹) of the samples of the solvate form (Class 3) (PP415-P6: top; PP415-P12: 2^(nd) from top; PP415-P20: 2^(nd) from bottom) are very similar to each other with only small differences, e.g., at 1690 cm⁻¹, but are clearly different from class 1 (PP415-P1: bottom). The spectra have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 98—PXRD patterns (2-32° 2θ) of the samples of the solvate form (Class 3) (PP415-P6: top; PP415-P12: middle; PP415-P20: bottom). The patterns have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 99—PXRD patterns (13.5-18.5° 2θ) of the samples of solvate form (Class 3) (PP415-P6: top; PP415-P12: middle; PP415-P20: bottom) show small differences. The patterns have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 100—TG-FTIR thermogram of the sample PP415-P6, which corresponds to the solvate form (Class 3).

FIG. 101—TG-FTIR thermogram of the sample PP415-P12, which corresponds to the solvate form (Class 3).

FIG. 102—TG-FTIR thermogram of the dried solvate form (Class 3), sample PP415-P25.

FIG. 103—TG-FTIR thermogram of the further dried solvate form (Class 3), sample PP415-P33.

FIG. 104—FT-Raman spectra (1800-700 cm⁻¹) of the solvate form (Class 3) (top, sample PP415-P6), of the dried solvate form (Class 3) (middle, sample PP415-P25), and of the further dried solvate form (Class 3) (bottom, sample PP415-P33) are identical. The spectra have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 105—PXRD patterns (4-24° 2θ) of the solvate form (Class 3) (top, sample PP415-P6), of the dried solvate form (Class 3) (middle, sample PP415-P25), and of the further dried solvate form (Class 3) (bottom, sample PP415-P33). The patterns have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 106—TG-FTIR thermogram of the sample PP415-P13, which corresponds to an acetonitrile solvate form (Class 4).

FIG. 107—FT-Raman spectra (1800-700 cm⁻¹) of the acetonitrile solvate form (Class 4) (dark grey, sample PP415-P13) and of the dried material of an acetonitrile solvate form (Class 4) (light grey, sample PP415-P26) are identical and overlay perfectly. The spectra have been scaled for purposes of comparison.

FIG. 108—PXRD pattern of the dried acetonitrile solvate form (Class 4), sample PP415-P26 (bottom), in comparison to the reference pattern of the acetonitrile solvate form (Class 4), sample PP415-P13 (top). The patterns have not been scaled but were offset in the y-direction for purposes of comparison.

FIG. 109—TG-FTIR thermogram of the dried acetonitrile solvate form (Class 4), sample PP415-P26.

FIG. 110—FT-Raman spectra (1800-700 cm⁻¹) of the acetonitrile solvate form (Class 4) (top, sample PP415-P35), and of the dried acetonitrile solvate form (Class 4) (middle, sample PP415-P36 and bottom, sample PP415-P37) correspond to each other. The spectra have been scaled and offset in the y-direction for purposes of comparison.

FIG. 111—PXRD patterns (4-24° 2θ) of the acetonitrile solvate form (Class 4) (top, sample PP415-P35) and of the dried acetonitrile solvate form (Class 4) (middle, sample PP415-P36 and bottom, sample PP415-P37) agree with each other. The patterns have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 112—TG-FTIR thermogram of the dried acetronitrile solvate form (Class 4), sample PP415-P36.

FIG. 113—TG-FTIR thermogram of the dried acetonitrile solvate form (Class 4), sample PP415-P37.

FIG. 114—DVS isotherm of the desolvated acetronitrile solvate form (Class 4), sample PP415-P37).

FIG. 115—PXRD pattern of the sample PP415-P37, an acetonitrile solvate form (Class 4) after the DVS measurement (bottom) is unchanged compared to the material before the DVS measurement (top). The patterns have not been scaled but are offset in the y-direction for the purpose of comparison.

FIG. 116—DSC thermogram of the desolvated acetonitrile solvate form (Class 4) (sample PP415-P37).

FIG. 117—DSC thermogram of a ˜1:1 mixture of the amorphous form (Class 1), sample PP415-P1, with the desolvated acetonitrile solvate form (Class 4), sample PP415-P36.

FIG. 118—DSC thermogram of a ˜1:1 mixture of the amorphous form (Class 1), sample PP415-P1, with the desolvated acetonitrile solvate form (Class 4), sample PP415-P36 (experiment number: PP415-P39). The heating scan (Step 1) was stopped for 30 min at 173° C. (Step 2) and then resumed (Step 3).

FIG. 119—TG-FTIR thermogram of the sample PP415-P14, which corresponds to a THF solvate form (Class 5).

FIG. 120—FT-Raman spectra (1800-1100 cm⁻¹) of a THF solvate form (Class 5) (dashed line, sample PP415-P14), dried material of a THF solvate form (Class 5) (dotted line, sample PP415-P27), and of the amorphous form (Class 1) (solid line, sample PP415-P1). The spectra have been scaled for the purpose of comparison and show small changes in magnitude but little corresponding change in spectral shape.

FIG. 121—PXRD pattern of the dried THF solvate form (Class 5), sample PP415-P27 (top) in comparison to the pattern of the THF solvate form (Class 5), sample PP415-P14 (bottom). The patterns have not been scaled but are offset in the y-direction for the purpose of comparison.

FIG. 122—TG-FTIR thermogram of the sample PP415-P27, which corresponds to a dried THF solvate (Class 5).

FIG. 123—PXRD pattern of sample PP415-P41 (top) corresponds to the pattern of the THF solvate form (Class 5) (middle, sample PP415-P14) and not to the pattern of the heptane solvate form, (Class 2) (bottom, sample PP415-P19). The patterns have been scaled and offset in the y-direction for purposes of comparison.

FIG. 124—PXRD pattern of sample PP415-P45 (top) corresponds to the pattern of the THF solvate form (Class 5) (middle, sample PP415-P14) and not to the pattern of the heptane solvate form (Class 2) (bottom, sample PP415-P19). The patterns have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 125—PXRD pattern of sample PP415-P41 (top) corresponds to a THF solvate form (Class 5). After drying sample PP415-P41 for 1 day (2^(nd) from top, sample: PP415-P44), the material is mainly amorphous. Some broad peaks with low intensity remain. After further drying overnight (2^(nd) from bottom, sample PP415-P44a) the intensity of these broad peaks is further reduced. The amorphous form (Class 1) is shown as a reference (bottom, sample: PP415-P42). The patterns have not been scaled but are offset in the y-direction for the purpose of comparison.

FIG. 126—TG-FTIR thermogram of the sample PP415-P44a, which corresponds to the amorphous form (Class 1).

FIG. 127—PXRD pattern of sample PP415-P45 (top) corresponds to a THF solvate form (Class 5). After drying sample PP415-P45 for 1 day (2^(nd) from top, sample PP415-P46), the material is mainly amorphous. Some broad peaks with low intensity remain. After a total of 4 days of drying (2^(nd) from bottom, sample PP415-P46a), the pattern remains unchanged. The amorphous form (Class 1) is shown as reference (bottom, sample PP415-P42). The patterns have not been scaled but are offset in the y-direction for the purpose of comparison.

FIG. 128—TG-FTIR thermogram of the sample PP415-P46a, which corresponds to the amorphous form (Class 1).

FIG. 129—PXRD pattern of sample PP415-P42 (top) corresponds to the pattern of the amorphous form (Class 1) (bottom, sample PP415-P1). The patterns have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 130—PXRD pattern of sample PP415-P43 (top) corresponds to the pattern of the isostructural solvate form (Class 2) (bottom, sample PP415-P19) and not to the pattern of the THF solvate form (Class 5) (middle, sample PP415-P14). The patterns have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 131—PXRD patterns of samples PP415-P47 (top) and PP415-P48 (middle) correspond essentially to the pattern of the isostructural solvate forms (Class 2) (bottom, sample PP415-P19), although there are some differences. The patterns have been scaled and offset in the y-direction for the purpose of comparison.

FIG. 132—PXRD pattern of sample PP415-P49 (top) corresponds to the pattern of the amorphous form (Class 1) (bottom, sample PP415-P1). The patterns have been scaled and offset in the y-direction for the purpose of comparison.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present invention provides in one aspect the compound:

-   N-((4aS,6aR,6bS,8aR,12aS,14aR,14bS)-11-cyano-2,2,6a,6b,9,9,12a-heptamethyl-10,14-dioxo-1,2,3,4,4a,5,6,6a,6b,7,8,8a,9,10,12a,14,14a,14b-octadecahydropicen-4a-yl)-2,2-difluoropropanamide,     which is also referred to herein as RTA 408, 63415, or PP415. In     other non-limiting aspects, the present invention also provides     polymorphic forms thereof, including solvates thereof. In other     non-limiting aspects, the invention also provides pharmaceutically     acceptable salts thereof. In other non-limiting aspects, there are     also provided methods for preparation, pharmaceutical compositions,     and kits and articles of manufacture of these compounds and     polymorphic forms thereof.

I. DEFINITIONS

When used in the context of a chemical group: “hydrogen” means —H; “hydroxy” means —OH; “oxo” means ═O; “carbonyl” means —C(═O)—; “carboxy” means —C(═O)OH (also written as —COOH or —CO₂H); “halo” means independently —F, —Cl, —Br or —I; “amino” means —NH₂; “hydroxyamino” means —NHOH; “nitro” means —NO₂; imino means ═NH; “cyano” means —CN; “isocyanate” means —N═C═O; “azido” means —N₃; in a monovalent context “phosphate” means —OP(O)(OH)₂ or a deprotonated form thereof; in a divalent context “phosphate” means —OP(O)(OH)O— or a deprotonated form thereof; “mercapto” means —SH; and “thio” means ═S; “sulfonyl” means —S(O)₂—; and “sulfinyl” means —S(O)—. Any undefined valency on an atom of a structure shown in this application implicitly represents a hydrogen atom bonded to the atom.

In the context of this disclosure, the formulas:

represent the same structures. When a dot is drawn on a carbon, the dot indicates that the hydrogen atom attached to that carbon is coming out of the plane of the page.

The use of the word “a” or “an,” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.”

Throughout this application, the term “about” is used to indicate that a value includes the inherent variation of error for the device, the method being employed to determine the value, or the variation that exists among the study subjects. When used in the context of X-ray powder diffraction, the term “about” is used to indicate a value of ±0.2° 2θ from the reported value, preferably a value of ±0.1° 2θ from the reported value. When used in the context of differential scanning calorimetry or glass transition temperatures, the term “about” is used to indicate a value of ±10° C. relative to the maximum of the peak, preferably a value of ±2° C. relative to the maximum of the peak. When used in other context, the term “about” is used to indicate a value of ±10% of the reported value, preferably a value of ±5% of the reported value. It is to be understood that, whenever the term “about” is used, a specific reference to the exact numerical value indicated is also included.

The terms “comprise,” “have” and “include” are open-ended linking verbs. Any forms or tenses of one or more of these verbs, such as “comprises,” “comprising,” “has,” “having,” “includes” and “including,” are also open-ended. For example, any method that “comprises,” “has” or “includes” one or more steps is not limited to possessing only those one or more steps and also covers other unlisted steps.

The term “effective,” as that term is used in the specification and/or claims, means adequate to accomplish a desired, expected, or intended result. “Effective amount,” “Therapeutically effective amount” or “pharmaceutically effective amount” when used in the context of treating a patient or subject with a compound means that amount of the compound which, when administered to a subject or patient for treating a disease, is sufficient to effect such treatment for the disease.

The term “halo peak” in the context of X-ray powder diffraction would mean a broad peak, often spanning >10° 2θ in an X-ray powder diffractogram, typically characteristic of an amorphous solid or system.

The term “hydrate” when used as a modifier to a compound means that the compound has less than one (e.g., hemihydrate), one (e.g., monohydrate), or more than one (e.g., dihydrate) water molecules associated with each compound molecule, such as in solid forms of the compound.

As used herein, the term “IC₅₀” refers to an inhibitory dose that is 50% of the maximum response obtained. This quantitative measure indicates how much of a particular drug or other substance (inhibitor) is needed to inhibit a given biological, biochemical, or chemical process (or component of a process, i.e. an enzyme, cell, cell receptor or microorganism) by half.

An “isomer” of a first compound is a separate compound in which each molecule contains the same constituent atoms as the first compound, but where the configuration of those atoms in three dimensions differs.

As used herein, the term “patient” or “subject” refers to a living mammalian organism, such as a human, monkey, cow, sheep, goat, dog, cat, mouse, rat, guinea pig, or transgenic species thereof. In certain embodiments, the patient or subject is a non-human animal. In certain embodiments, the patient or subject is a primate. In certain embodiments, the patient or subject is a human. Non-limiting examples of human subjects are adults, juveniles, infants and fetuses.

As generally used herein “pharmaceutically acceptable” refers to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues, organs, and/or bodily fluids of human beings and animals without excessive toxicity, irritation, allergic response, or other problems or complications commensurate with a reasonable benefit/risk ratio.

“Pharmaceutically acceptable salts” means salts of compounds of the present invention which are pharmaceutically acceptable, as defined above, and which possess the desired pharmacological activity. Such salts include acid addition salts formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like; or with organic acids such as 1,2-ethanedisulfonic acid, 2-hydroxyethanesulfonic acid, 2-naphthalenesulfonic acid, 3-phenylpropionic acid, 4,4′-methylenebis(3-hydroxy-2-ene-1-carboxylic acid), 4-methylbicyclo[2.2.2]oct-2-ene-1-carboxylic acid, acetic acid, aliphatic mono- and dicarboxylic acids, aliphatic sulfuric acids, aromatic sulfuric acids, benzenesulfonic acid, benzoic acid, camphorsulfonic acid, carbonic acid, cinnamic acid, citric acid, cyclopentanepropionic acid, ethanesulfonic acid, fumaric acid, glucoheptonic acid, gluconic acid, glutamic acid, glycolic acid, heptanoic acid, hexanoic acid, hydroxynaphthoic acid, lactic acid, laurylsulfuric acid, maleic acid, malic acid, malonic acid, mandelic acid, methanesulfonic acid, muconic acid, o-(4-hydroxybenzoyl)benzoic acid, oxalic acid, p-chlorobenzenesulfonic acid, phenyl-substituted alkanoic acids, propionic acid, p-toluenesulfonic acid, pyruvic acid, salicylic acid, stearic acid, succinic acid, tartaric acid, tertiarybutylacetic acid, trimethylacetic acid, and the like. Pharmaceutically acceptable salts also include base addition salts which may be formed when acidic protons present are capable of reacting with inorganic or organic bases. Acceptable inorganic bases include sodium hydroxide, sodium carbonate, potassium hydroxide, aluminum hydroxide and calcium hydroxide. Acceptable organic bases include ethanolamine, diethanolamine, triethanolamine, tromethamine, N-methylglucamine and the like. It should be recognized that the particular anion or cation forming a part of any salt of this invention is not critical, so long as the salt, as a whole, is pharmacologically acceptable. Additional examples of pharmaceutically acceptable salts and their methods of preparation and use are presented in Handbook of Pharmaceutical Salts: Properties, and Use (P. H. Stahl & C. G. Wermuth eds., Verlag Helvetica Chimica Acta, 2002).

“Prevention” or “preventing” includes: (1) inhibiting the onset of a disease in a subject or patient which may be at risk and/or predisposed to the disease but does not yet experience or display any or all of the pathology or symptomatology of the disease, and/or (2) slowing the onset of the pathology or symptomatology of a disease in a subject or patient which may be at risk and/or predisposed to the disease but does not yet experience or display any or all of the pathology or symptomatology of the disease.

“Prodrug” means a compound that is convertible in vivo metabolically into an inhibitor according to the present invention. The prodrug itself may or may not also have activity with respect to a given target protein. For example, a compound comprising a hydroxy group may be administered as an ester that is converted by hydrolysis in vivo to the hydroxy compound. Suitable esters that may be converted in vivo into hydroxy compounds include acetates, citrates, lactates, phosphates, tartrates, malonates, oxalates, salicylates, propionates, succinates, fumarates, maleates, methylene-bis-β-hydroxynaphthoate, gentisates, isethionates, di-p-toluoyltartrates, methane-sulfonates, ethanesulfonates, benzenesulfonates, p-toluenesulfonates, cyclohexyl-sulfamates, quinates, esters of amino acids, and the like. Similarly, a compound comprising an amine group may be administered as an amide that is converted by hydrolysis in vivo to the amine compound.

A “stereoisomer” or “optical isomer” is an isomer of a given compound in which the same atoms are bonded to the same other atoms, but where the configuration of those atoms in three dimensions differs. “Enantiomers” are stereoisomers of a given compound that are mirror images of each other, like left and right hands. “Diastereomers” are stereoisomers of a given compound that are not enantiomers. Chiral molecules contain a chiral center, also referred to as a stereocenter or stereogenic center, which is any point, though not necessarily an atom, in a molecule bearing groups such that an interchanging of any two groups leads to a stereoisomer. In organic compounds, the chiral center is typically a carbon, phosphorus or sulfur atom, though it is also possible for other atoms to be stereocenters in organic and inorganic compounds. A molecule can have multiple stereocenters, giving it many stereoisomers. In compounds whose stereoisomerism is due to tetrahedral stereogenic centers (e.g., tetrahedral carbon), the total number of hypothetically possible stereoisomers will not exceed 2n, where n is the number of tetrahedral stereocenters. Molecules with symmetry frequently have fewer than the maximum possible number of stereoisomers. A 50:50 mixture of enantiomers is referred to as a racemic mixture. Alternatively, a mixture of enantiomers can be enantiomerically enriched so that one enantiomer is present in an amount greater than 50%. Typically, enantiomers and/or diastereomers can be resolved or separated using techniques known in the art. It is contemplated that for any stereocenter or axis of chirality for which stereochemistry has not been defined, that stereocenter or axis of chirality can be present in its R form, S form, or as a mixture of the R and S forms, including racemic and non-racemic mixtures. As used herein, the phrase “substantially free from other stereoisomers” means that the composition contains ≦15%, more preferably ≦10%, even more preferably ≦5%, or most preferably ≦1% of another stereoisomer(s).

“Treatment” or “treating” includes (1) inhibiting a disease in a subject or patient experiencing or displaying the pathology or symptomatology of the disease (e.g., arresting further development of the pathology and/or symptomatology), (2) ameliorating a disease in a subject or patient that is experiencing or displaying the pathology or symptomatology of the disease (e.g., reversing the pathology and/or symptomatology), and/or (3) effecting any measurable decrease in a disease in a subject or patient that is experiencing or displaying the pathology or symptomatology of the disease.

The above definitions supersede any conflicting definition in any of the reference that is incorporated by reference herein. The fact that certain terms are defined, however, should not be considered as indicative that any term that is undefined is indefinite. Rather, all terms used are believed to describe the invention in terms such that one of ordinary skill can appreciate the scope and practice the present invention.

II. RTA 408 AND SYNTHETIC METHODS

RTA 408 can be prepared according to the methods described in the Examples section below. These methods can be further modified and optimized using the principles and techniques of organic chemistry as applied by a person skilled in the art. Such principles and techniques are taught, for example, in March's Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (2007), which is incorporated by reference herein.

It should be recognized that the particular anion or cation forming a part of any salt of this invention is not critical, so long as the salt, as a whole, is pharmacologically acceptable. Additional examples of pharmaceutically acceptable salts and their methods of preparation and use are presented in Handbook of Pharmaceutical Salts: Properties, and Use (2002), which is incorporated herein by reference.

RTA 408 may also exist in prodrug form. Since prodrugs are known to enhance numerous desirable qualities of pharmaceuticals, e.g., solubility, bioavailability, manufacturing, etc., the compounds employed in some methods of the invention may, if desired, be delivered in prodrug form. Thus, the invention contemplates prodrugs of compounds of the present invention as well as methods of delivering prodrugs. Prodrugs of the compounds employed in the invention may be prepared by modifying functional groups present in the compound in such a way that the modifications are cleaved, either in routine manipulation or in vivo, to the parent compound. Accordingly, prodrugs include, for example, compounds described herein in which a hydroxy, amino, or carboxy group is bonded to any group that, when the prodrug is administered to a patient, cleaves to form a hydroxy, amino, or carboxylic acid, respectively.

RTA 408 may contain one or more asymmetrically-substituted carbon or nitrogen atoms, and may be isolated in optically active or racemic form. Thus, all chiral, diastereomeric, racemic form, epimeric form, and all geometric isomeric forms of a structure are intended, unless the specific stereochemistry or isomeric form is specifically indicated. RTA 408 may occur as racemates and racemic mixtures, single enantiomers, diastereomeric mixtures and individual diastereomers. In some embodiments, a single diastereomer is obtained. The chiral centers of RTA 408 according to the present invention can have the S or the R configuration.

In addition, atoms making up RTA 408 of the present invention are intended to include all isotopic forms of such atoms. Isotopes, as used herein, include those atoms having the same atomic number but different mass numbers. By way of general example and without limitation, isotopes of hydrogen include tritium and deuterium, and isotopes of carbon include ¹³C and ¹⁴C. Similarly, it is contemplated that one or more carbon atom(s) of a compound of the present invention may be replaced by a silicon atom(s). Furthermore, it is contemplated that one or more oxygen atom(s) of RTA 408 may be replaced by a sulfur or selenium atom(s).

RTA 408 and polymorphic form thereof may also have the advantage that they may be more efficacious than, be less toxic than, be longer acting than, be more potent than, produce fewer side effects than, be more easily absorbed than, and/or have a better pharmacokinetic profile (e.g., higher oral bioavailability and/or lower clearance) than, and/or have other useful pharmacological, physical, or chemical advantages over, compounds known in the prior art for use in the indications stated herein.

III. POLYMORPHIC FORMS OF RTA 408

In some embodiments, the present invention provides different solid forms of RTA 408, including solvates thereof. A preformulation and preliminary polymorphism study was performed, and RTA 408 was found to have a high tendency for solvate formation. Crystalline forms of classes 2, 3, 4, and 5 are consistent with solvates. For a description of the classes, see Table 1 below. Attempts to dry classes 2 and 3 (two groups of isostructural solvates) were not successful, which is consistent with tightly bound solvent molecules. In some embodiments, drying of a class 4 solid (acetonitrile solvate) led to an isostructural desolvated form. In some embodiments, drying of a class 5 solid (THF solvate) resulted in the amorphous form class 1. Non-solvated forms of RTA 408 include the amorphous form (class 1) and the crystalline desolvated solvate of class 4 (isostructural to the class 4 acetonitrile solvate). In some embodiments, the amorphous form has a high glass transition with T_(g)≈153° C. (ΔCp=0.72 J/g° C.) and is only slightly hygroscopic (Δm=+0.4% 50%→85% r.h.). In some embodiments, the amorphous form is stable for at least four weeks under elevated temperature and humidity conditions (i.e., open at 40° C./˜75% r.h. or closed at 80° C.). In some embodiments, the amorphous form (class 1) was successfully prepared from class 2 material in a two-step process (transformation into class 5 and subsequent drying of class 5 to obtain the amorphous form), as well as in a direct one-step method (precipitation from an acetone solution in a cold water bath). The crystalline desolvated solvate of class 4 (isostructural to the class 4 solvate) is slightly hygroscopic (mass gain of ˜0.7 wt.-% from 50% r.h. to 85% r.h.) and has a possible melting point at 196.1° C. (ΔH=29.31 J/g).

A sample of the amorphous form of 63415, class 1, was characterized by FT-Raman spectroscopy, PXRD, TG-FTIR, Karl Fischer titration, ¹H-NMR, DSC, and DVS (see Examples section for additional details). The sample was found to contain ˜0.9 wt.-% EtOH with traces of H₂O (according to the TG-FTIR). A water content of 0.5 wt.-% was determined by Karl Fischer titration. DSC shows a high glass transition temperature with T_(g)≈153° C. (ΔC_(p)=0.72 J/g° C.). According to DVS, the material is slightly hygroscopic (Δm=+0.4% 50%→85% r.h.). No crystallization was observed in the DSC or DVS experiments.

The chemical stability of the amorphous form was investigated in organic solvents, including acetone, EtOAc, MeOH, and MeCN, as well as different aqueous media (e.g., 1% aq. Tween 80, 1% aq. SDS, 1% aq. CTAB) at a concentration of 1 mg/mL at time points 6 h, 24 h, 2 d, and 7 d. Decomposition ≧1% was observed only for solutions in MeCN after 7 days and for suspensions in the 1% aqueous Tween 80 medium (at all times points at 254 nm and after 24 h, 2 d, and 7 d at 242 nm).

In addition, the stability of the amorphous form was investigated by storage under elevated temperature and humidity conditions (open at 25° C./62% r.h. and 40° C./75% r.h. and closed at 60° C. and 80° C.). After one week, two weeks, and four weeks, the stored samples were analyzed by PXRD. None of the samples differed from the amorphous starting material.

More than 30 crystallization and drying experiments were carried out, including suspension equilibration, slow cooling, evaporation, and precipitation. Four new crystalline forms were obtained (classes 2, 3, 4, and 5) in addition to the amorphous form (class 1).

The four new forms (classes 2, 3, 4, and 5) were characterized by FT-Raman spectroscopy, PXRD, and TG-FTIR. All forms correspond to solvates (Table 1). Drying experiments under vacuum or N₂ flow were carried out with the aim to obtain a crystalline, non-solvated form of 63415.

TABLE 1 Summary of Obtained Classes Result of Class Characteristics Drying Experiments Class 1 amorphous form — Class 2 isostructural solvates (e.g., heptane) drying not successful Class 3 isostructural solvates (e.g., ethanol) drying not successful Class 4 MeCN solvate & desolvated solvate drying successful, structure unchanged Class 5 THF solvate drying resulted in amorphous form

Class 2: Most crystallization experiments that were conducted resulted in solid material of class 2 (see Examples section below). Its members may correspond to isostructural, non-stoichiometric (<0.5 eq.) solvates (of heptane, cyclohexane, isopropyl ether, 1-butanol, triethylamine, and possibly other solvents, such as hexane, other ethers, etc.) with tightly bound solvent molecules. The Raman spectra and PXRD patterns within this class are very similar to each other, thus the structures might be essentially identical with only small differences due to the different solvents that were incorporated.

Drying experiments on class 2 samples have not resulted in a crystalline, non-solvated form. Even elevated temperatures (80° C.) and a high vacuum (<1×10⁻³ mbar) could not remove the tightly bound solvent molecules completely; a solvent content of >2 wt.-% always remained. The crystallinity of these partially dried samples is reduced, but neither transformation into a different structure nor substantial amorphization was observed.

Class 3: Solid material of class 3 may be obtained from several crystallizations (see Examples section below). The samples of class 3 are likely isostructural solvates of 2PrOH, EtOH, and probably acetone with tightly bound solvent molecules. They could correspond to either stoichiometric hemisolvates or non-stoichiometric solvates with a solvent content of ˜0.5 eq. As with class 2, the Raman spectra and PXRD patterns within this class are very similar to each other, indicating similar structures that incorporate different solvents.

Similar to class 2, drying experiments were not successful. The very tightly bound solvent molecules could only partially be removed (i.e., ˜5.4 wt.-% to ˜4.8 wt.-% after up to 3 d at 1×10⁻³ mbar and 80° C.). The PXRD patterns remained unchanged.

Class 4 may be obtained from a 7:3 MeCN/H₂O solvent system (see Examples section below). It most likely corresponds to a crystalline acetonitrile hemisolvate. By drying (under vacuum or N₂ flow at elevated temperatures) most of the solvent molecules could be removed without changing or destroying the crystal structure (PXRD remained unchanged). Thus, a crystalline, non-solvated form (or rather desolvated solvate) was obtained. It is slightly hygroscopic (mass gain of ˜0.7 wt.-% from 50% r.h. to 85% r.h.) and has a possible melting point at 196.1° C. (ΔH=29.31 J/g).

Class 5 may be obtained from an ˜1:1 THF/H₂O solvent system. Class 5 contains bound THF (and maybe H₂O). As the content of the two components cannot be readily quantified separately, the exact nature of this crystalline solvate has not been determined.

Drying of class 5 resulted in significant desolvation and transformation in the direction of the amorphous form (class 1). In some embodiments, the amorphous form of RTA 408 may be prepared by suspending class 2 heptane solvate in 1:1 THF/H₂O to form a class 5 solid, followed by drying and amorphization.

Experiments with the aim of preparing the amorphous form (class 1) were carried out using class 2 starting material. Mainly amorphous material (class 1) was prepared starting from class 2 material in a two-step process via class 5 on a 100-mg and 3-g scale (drying at 100 mbar, 80° C., several days). The preparation of fully amorphous material (class 1) was found to be possible in a one-step process avoiding the solvent THF by direct precipitation of the amorphous form (class 1) from an acetone solution of class 2 material in a cold water bath.

IV. DISEASES ASSOCIATED WITH INFLAMMATION AND/OR OXIDATIVE STRESS

Inflammation is a biological process that provides resistance to infectious or parasitic organisms and the repair of damaged tissue. Inflammation is commonly characterized by localized vasodilation, redness, swelling, and pain, the recruitment of leukocytes to the site of infection or injury, production of inflammatory cytokines, such as TNF-α and IL-1, and production of reactive oxygen or nitrogen species, such as hydrogen peroxide, superoxide, and peroxynitrite. In later stages of inflammation, tissue remodeling, angiogenesis, and scar formation (fibrosis) may occur as part of the wound healing process. Under normal circumstances, the inflammatory response is regulated, temporary, and is resolved in an orchestrated fashion once the infection or injury has been dealt with adequately. However, acute inflammation can become excessive and life-threatening if regulatory mechanisms fail. Alternatively, inflammation can become chronic and cause cumulative tissue damage or systemic complications. Based at least on the evidence presented herein, RTA 408 can be used in the treatment or prevention of inflammation or diseases associated with inflammation.

Many serious and intractable human diseases involve dysregulation of inflammatory processes, including diseases such as cancer, atherosclerosis, and diabetes, which were not traditionally viewed as inflammatory conditions. In the case of cancer, the inflammatory processes are associated with processes that include tumor formation, progression, metastasis, and resistance to therapy. In some embodiments, RTA 408 may be used in the treatment or prevention of cancers including a carcinoma, sarcoma, lymphoma, leukemia, melanoma, mesothelioma, multiple myeloma, or seminoma, or cancer of the bladder, blood, bone, brain, breast, central nervous system, cervix, colon, endometrium, esophagus, gall bladder, genitalia, genitourinary tract, head, kidney, larynx, liver, lung, muscle tissue, neck, oral or nasal mucosa, ovary, pancreas, prostate, skin, spleen, small intestine, large intestine, stomach, testicle, or thyroid. Atherosclerosis, long viewed as a disorder of lipid metabolism, is now understood to be primarily an inflammatory condition, with activated macrophages playing an important role in the formation and eventual rupture of atherosclerotic plaques. Activation of inflammatory signaling pathways has also been shown to play a role in the development of insulin resistance, as well as in the peripheral tissue damage associated with diabetic hyperglycemia. Excessive production of reactive oxygen species and reactive nitrogen species, such as superoxide, hydrogen peroxide, nitric oxide, and peroxynitrite, is a hallmark of inflammatory conditions. Evidence of dysregulated peroxynitrite production has been reported in a wide variety of diseases (Szabo et al., 2007; Schulz et al., 2008; Forstermann, 2006; Pall, 2007).

Autoimmune diseases such as rheumatoid arthritis, lupus, psoriasis, and multiple sclerosis involve inappropriate and chronic activation of inflammatory processes in affected tissues, arising from dysfunction of self vs. non-self recognition and response mechanisms in the immune system. In neurodegenerative diseases such as Alzheimer's and Parkinson's diseases, neural damage is correlated with activation of microglia and elevated levels of pro-inflammatory proteins, such as inducible nitric oxide synthase (iNOS). Chronic organ failure, such as renal failure, heart failure, liver failure, and chronic obstructive pulmonary disease, is closely associated with the presence of chronic oxidative stress and inflammation, leading to the development of fibrosis and eventual loss of organ function. Oxidative stress in vascular endothelial cells, which line major and minor blood vessels, can lead to endothelial dysfunction and is believed to be an important contributing factor in the development of systemic cardiovascular disease, complications of diabetes, chronic kidney disease and other forms of organ failure, and a number of other aging-related diseases, including degenerative diseases of the central nervous system and the retina.

Many other disorders involve oxidative stress and inflammation in affected tissues, including inflammatory bowel disease; inflammatory skin diseases; mucositis and dermatitis related to radiation therapy and chemotherapy; eye diseases, such as uveitis, glaucoma, macular degeneration, and various forms of retinopathy; transplant failure and rejection; ischemia-reperfusion injury; chronic pain; degenerative conditions of the bones and joints, including osteoarthritis and osteoporosis; asthma and cystic fibrosis; seizure disorders; and neuropsychiatric conditions, including schizophrenia, depression, bipolar disorder, post-traumatic stress disorder, attention deficit disorders, autism-spectrum disorders, and eating disorders, such as anorexia nervosa. Dysregulation of inflammatory signaling pathways is believed to be a major factor in the pathology of muscle wasting diseases, including muscular dystrophy and various forms of cachexia.

A variety of life-threatening acute disorders also involve dysregulated inflammatory signaling, including acute organ failure involving the pancreas, kidneys, liver, or lungs, myocardial infarction or acute coronary syndrome, stroke, septic shock, trauma, severe burns, and anaphylaxis.

Many complications of infectious diseases also involve dysregulation of inflammatory responses. Although an inflammatory response can kill invading pathogens, an excessive inflammatory response can also be quite destructive and in some cases can be a primary source of damage in infected tissues. Furthermore, an excessive inflammatory response can also lead to systemic complications due to overproduction of inflammatory cytokines, such as TNF-α and IL-1. This is believed to be a factor in mortality arising from severe influenza, severe acute respiratory syndrome, and sepsis.

The aberrant or excessive expression of either iNOS or cyclooxygenase-2 (COX-2) has been implicated in the pathogenesis of many disease processes. For example, it is clear that NO is a potent mutagen (Tamir and Tannebaum, 1996), and that nitric oxide can also activate COX-2 (Salvemini et al., 1994). Furthermore, there is a marked increase in iNOS in rat colon tumors induced by the carcinogen, azoxymethane (Takahashi et al., 1997). A series of synthetic triterpenoid analogs of oleanolic acid have been shown to be powerful inhibitors of cellular inflammatory processes, such as the induction by IFN-γ of inducible nitric oxide synthase (iNOS) and of COX-2 in mouse macrophages. See Honda et al. (2000a), Honda et al. (2000b), and Honda et al. (2002), which are all incorporated herein by reference.

In one aspect, RTA 408 disclosed herein is in part characterized by its ability to inhibit the production of nitric oxide in macrophage-derived RAW 264.7 cells induced by exposure to γ-interferon. RTA 408 is further characterized by the ability to induce the expression of antioxidant proteins, such as NQO1, and reduce the expression of pro-inflammatory proteins, such as COX-2 and inducible nitric oxide synthase (iNOS). These properties are relevant to the treatment of a wide array of diseases and disorders involving oxidative stress and dysregulation of inflammatory processes, including cancer, complications from localized or total-body exposure to ionizing radiation, mucositis and dermatitis resulting from radiation therapy or chemotherapy, autoimmune diseases, cardiovascular diseases, including atherosclerosis, ischemia-reperfusion injury, acute and chronic organ failure, including renal failure and heart failure, respiratory diseases, diabetes and complications of diabetes, severe allergies, transplant rejection, graft-versus-host disease, neurodegenerative diseases, diseases of the eye and retina, acute and chronic pain, degenerative bone diseases, including osteoarthritis and osteoporosis, inflammatory bowel diseases, dermatitis and other skin diseases, sepsis, burns, seizure disorders, and neuropsychiatric disorders.

In another aspect, RTA 408 may be used for treating a subject having a condition such as eye diseases. For example, uveitis, macular degeneration (both the dry form and wet form), glaucoma, diabetic macular edema, blepharitis, diabetic retinopathy, diseases and disorders of the corneal endothelium such as Fuchs endothelial corneal dystrophy, post-surgical inflammation, dry eye, allergic conjunctivitis and other forms of conjunctivitis are non-limiting examples of eye diseases that could be treated with RTA 408.

In another aspect, RTA 408 may be used for treating a subject having a condition such as skin diseases or disorders. For example, dermatitis, including allergic dermatitis, atopic dermatitis, dermatitis due to chemical exposure, and radiation-induced dermatitis; thermal or chemical burns; chronic wounds including diabetic ulcers, pressure sores, and venous ulcers; acne; alopecia including baldness and drug-induced alopecia; other disorders of the hair follicle; epidermolysis bullosa; sunburn and its complications; disorders of skin pigmentation including vitiligo; aging-related skin conditions; post-surgical wound healing; prevention or reduction of scarring from skin injury, surgery, or burns; psoriasis; dermatological manifestations of autoimmune diseases or graft-versus host disease; prevention or treatment of skin cancer; disorders involving hyperproliferation of skin cells such as hyperkeratosis is a non-limiting example of skin diseases that could be treated with RTA 408.

Without being bound by theory, the activation of the antioxidant/anti-inflammatory Keap1/Nrf2/ARE pathway is believed to be implicated in both the anti-inflammatory and anti-carcinogenic properties of the compound disclosed herein.

In another aspect, RTA 408 may be used for treating a subject having a condition caused by elevated levels of oxidative stress in one or more tissues. Oxidative stress results from abnormally high or prolonged levels of reactive oxygen species, such as superoxide, hydrogen peroxide, nitric oxide, and peroxynitrite (formed by the reaction of nitric oxide and superoxide). The oxidative stress may be accompanied by either acute or chronic inflammation. The oxidative stress may be caused by mitochondrial dysfunction, by activation of immune cells, such as macrophages and neutrophils, by acute exposure to an external agent, such as ionizing radiation or a cytotoxic chemotherapeutic agent (e.g., doxorubicin), by trauma or other acute tissue injury, by ischemia/reperfusion, by poor circulation or anemia, by localized or systemic hypoxia or hyperoxia, by elevated levels of inflammatory cytokines and other inflammation-related proteins, and/or by other abnormal physiological states, such as hyperglycemia or hypoglycemia.

In animal models of many such conditions, stimulating expression of inducible heme oxygenase (HO-1), a target gene of the Nrf2 pathway, has been shown to have a significant therapeutic effect including in models of myocardial infarction, renal failure, transplant failure and rejection, stroke, cardiovascular disease, and autoimmune disease (e.g., Sacerdoti et al., 2005; Abraham & Kappas, 2005; Bach, 2006; Araujo et al., 2003; Liu et al., 2006; Ishikawa et al., 2001; Kruger et al., 2006; Satoh et al., 2006; Zhou et al., 2005; Morse and Choi, 2005; Morse and Choi, 2002). This enzyme breaks free heme down into iron, carbon monoxide (CO), and biliverdin (which is subsequently converted to the potent antioxidant molecule, bilirubin).

In another aspect, RTA 408 may be used in preventing or treating tissue damage or organ failure, acute and chronic, resulting from oxidative stress exacerbated by inflammation. Examples of diseases that fall in this category include heart failure, liver failure, transplant failure and rejection, renal failure, pancreatitis, fibrotic lung diseases (cystic fibrosis, COPD, and idiopathic pulmonary fibrosis, among others), diabetes (including complications), atherosclerosis, ischemia-reperfusion injury, glaucoma, stroke, autoimmune disease, autism, macular degeneration, and muscular dystrophy. For example, in the case of autism, studies suggest that increased oxidative stress in the central nervous system may contribute to the development of the disease (Chauhan and Chauhan, 2006).

Evidence also links oxidative stress and inflammation to the development and pathology of many other disorders of the central nervous system, including psychiatric disorders, such as psychosis, major depression, and bipolar disorder; seizure disorders, such as epilepsy; pain and sensory syndromes, such as migraine, neuropathic pain, or tinnitus; and behavioral syndromes, such as the attention deficit disorders. See, e.g., Dickerson et al., 2007; Hanson et al., 2005; Kendall-Tackett, 2007; Lencz et al., 2007; Dudhgaonkar et al., 2006; Lee et al., 2007; Morris et al., 2002; Ruster et al., 2005; McIver et al., 2005; Sarchielli et al., 2006; Kawakami et al., 2006; Ross et al., 2003, which are all incorporated by reference herein. For example, elevated levels of inflammatory cytokines, including TNF-α, interferon-γ, and IL-6, are associated with major mental illness (Dickerson et al., 2007). Microglial activation has also been linked to major mental illness. Therefore, downregulating inflammatory cytokines and inhibiting excessive activation of microglia could be beneficial in patients with schizophrenia, major depression, bipolar disorder, autism-spectrum disorders, and other neuropsychiatric disorders.

Accordingly, in pathologies involving oxidative stress alone or oxidative stress exacerbated by inflammation, treatment may comprise administering to a subject a therapeutically effective amount of a compound of this invention, such as those described above or throughout this specification. Treatment may be administered preventively, in advance of a predictable state of oxidative stress (e.g., organ transplantation or the administration of radiation therapy to a cancer patient), or it may be administered therapeutically in settings involving established oxidative stress and inflammation. In some embodiments, when a compound of the present invention is used for treating a patient receiving radiation therapy and/or chemotherapy, the compound of the invention may be administered before, at the same time, and/or after the radiation or chemotherapy, or the compound may be administered in combination with the other therapies. In some embodiments, the compound of the invention may prevent and/or reduce the severity of side effects associated with the radiation therapy or chemotherapy (using a different agent) without reducing the anticancer effects of the radiation therapy or chemotherapy. Because such side effects may be dose-limiting for the radiation therapy and/or chemotherapy, in some embodiments, the compound of the present invention may be used to allow for higher and/or more frequent dosing of the radiation therapy and/or chemotherapy, for example, resulting in greater treatment efficacy. In some embodiments, the compound of the invention when administered in combination with the radiation therapy and/or chemotherapy may enhance the efficacy of a given dose of radiation and/or chemotherapy. In some embodiments, the compound of the invention when administered in combination with the radiation therapy and/or chemotherapy may enhance the efficacy of a given dose of radiation and/or chemotherapy and reduce (or, at a minimum, not add to) the side effects of the radiation and/or chemotherapy. In some embodiments, and without being bound by theory, this combinatorial efficacy may result from inhibition of the activity of the pro-inflammatory transcription factor NF-κB by the compound of the invention. NF-κB is often chronically activated in cancer cells, and such activation is associated with resistance to therapy and promotion of tumor progression (e.g., Karin, 2006; Aghajan et al., 2012). Other transcription factors that promote inflammation and cancer, such as STAT3 (e.g., He and Karin 2011; Grivennikov and Karin, 2010), may also be inhibited by the compound of the invention in some embodiments.

RTA 408 may be used to treat or prevent inflammatory conditions, such as sepsis, dermatitis, autoimmune disease, and osteoarthritis. RTA 408 may also be used to treat or prevent inflammatory pain and/or neuropathic pain, for example, by inducing Nrf2 and/or inhibiting NF-κB.

RTA 408 may also be used to treat or prevent diseases, such as cancer, inflammation, Alzheimer's disease, Parkinson's disease, multiple sclerosis, autism, amyotrophic lateral sclerosis, Huntington's disease, autoimmune diseases, such as rheumatoid arthritis, lupus, Crohn's disease, and psoriasis, inflammatory bowel disease, all other diseases whose pathogenesis is believed to involve excessive production of either nitric oxide or prostaglandins, and pathologies involving oxidative stress alone or oxidative stress exacerbated by inflammation. RTA 408 may be used in the treatment or prevention of cancers include a carcinoma, sarcoma, lymphoma, leukemia, melanoma, mesothelioma, multiple myeloma, or seminoma, or cancer of the bladder, blood, bone, brain, breast, central nervous system, cervix, colon, endometrium, esophagus, gall bladder, genitalia, genitourinary tract, head, kidney, larynx, liver, lung, muscle tissue, neck, oral or nasal mucosa, ovary, pancreas, prostate, skin, spleen, small intestine, large intestine, stomach, testicle, or thyroid.

Another aspect of inflammation is the production of inflammatory prostaglandins, such as prostaglandin E. RTA 408 may be used to promote vasodilation, plasma extravasation, localized pain, elevated temperature, and other symptoms of inflammation. The inducible form of the enzyme COX-2 is associated with their production, and high levels of COX-2 are found in inflamed tissues. Consequently, inhibition of COX-2 may relieve many symptoms of inflammation and a number of important anti-inflammatory drugs (e.g., ibuprofen and celecoxib) act by inhibiting COX-2 activity. It has been demonstrated that a class of cyclopentenone prostaglandins (cyPGs) (e.g., 15-deoxy prostaglandin J2, a.k.a. PGJ2) plays a role in stimulating the orchestrated resolution of inflammation (e.g., Rajakariar et al., 2007). COX-2 is also associated with the production of cyclopentenone prostaglandins. Consequently, inhibition of COX-2 may interfere with the full resolution of inflammation, potentially promoting the persistence of activated immune cells in tissues and leading to chronic, “smoldering” inflammation. This effect may be responsible for the increased incidence of cardiovascular disease in patients using selective COX-2 inhibitors for long periods of time.

In one aspect, RTA 408 may be used to control the production of pro-inflammatory cytokines within the cell by selectively activating regulatory cysteine residues (RCRs) on proteins that regulate the activity of redox-sensitive transcription factors. Activation of RCRs by cyPGs has been shown to initiate a pro-resolution program in which the activity of the antioxidant and cytoprotective transcription factor Nrf2 is potently induced and the activities of the pro-oxidant and pro-inflammatory transcription factors NF-κB and the STATs are suppressed. In some embodiments, RTA 408 may be used to increase the production of antioxidant and reductive molecules (NQO1, HO-1, SOD1, γ-GCS) and decrease oxidative stress and the production of pro-oxidant and pro-inflammatory molecules (iNOS, COX-2, TNF-α). In some embodiments, RTA 408 may be used to cause the cells that host the inflammatory event to revert to a non-inflammatory state by promoting the resolution of inflammation and limiting excessive tissue damage to the host.

A. Cancer

In some embodiments, RTA 408, the polymorphic forms, and methods of the present disclosure may be used to induce apoptosis in tumor cells, to induce cell differentiation, to inhibit cancer cell proliferation, to inhibit an inflammatory response, and/or to function in a chemopreventative capacity. For example, the invention provides new polymorphic forms that have one or more of the following properties: (1) an ability to induce apoptosis and differentiate both malignant and non-malignant cells, (2) an activity at sub-micromolar or nanomolar levels as an inhibitor of proliferation of many malignant or premalignant cells, (3) an ability to suppress the de novo synthesis of the inflammatory enzyme inducible nitric oxide synthase (iNOS), (4) an ability to inhibit NF-κB activation, and (5) an ability to induce the expression of heme oxygenase-1 (HO-1).

The levels of iNOS and COX-2 are elevated in certain cancers and have been implicated in carcinogenesis and COX-2 inhibitors have been shown to reduce the incidence of primary colonic adenomas in humans (Rostom et al., 2007; Brown and DuBois, 2005; Crowel et al., 2003). iNOS is expressed in myeloid-derived suppressor cells (MDSCs) (Angulo et al., 2000) and COX-2 activity in cancer cells has been shown to result in the production of prostaglandin E₂ (PGE₂), which has been shown to induce the expression of arginase in MDSCs (Sinha et al., 2007). Arginase and iNOS are enzymes that utilize L-arginine as a substrate and produce L-ornithine and urea, and L-citrulline and NO, respectively. The depletion of arginine from the tumor microenvironment by MDSCs, combined with the production of NO and peroxynitrite has been shown to inhibit proliferation and induce apoptosis of T cells (Bronte et al., 2003) Inhibition of COX-2 and iNOS has been shown to reduce the accumulation of MDSCs, restore cytotoxic activity of tumor-associated T cells, and delay tumor growth (Sinha et al., 2007; Mazzoni et al., 2002; Zhou et al., 2007).

Inhibition of the NF-κB and JAK/STAT signaling pathways has been implicated as a strategy to inhibit proliferation of cancer epithelial cells and induce their apoptosis. Activation of STAT3 and NF-κB has been shown to result in suppression of apoptosis in cancer cells, and promotion of proliferation, invasion, and metastasis. Many of the target genes involved in these processes have been shown to be transcriptionally regulated by both NF-κB and STAT3 (Yu et al., 2007).

In addition to their direct roles in cancer epithelial cells, NF-κB and STAT3 also have important roles in other cells found within the tumor microenvironment. Experiments in animal models have demonstrated that NF-κB is required in both cancer cells and hematopoeitic cells to propagate the effects of inflammation on cancer initiation and progression (Greten et al., 2004). NF-κB inhibition in cancer and myeloid cells reduces the number and size, respectively, of the resultant tumors. Activation of STAT3 in cancer cells results in the production of several cytokines (IL-6, IL-10) which suppress the maturation of tumor-associated dendritic cells (DC). Furthermore, STAT3 is activated by these cytokines in the dendritic cells themselves. Inhibition of STAT3 in mouse models of cancer restores DC maturation, promotes antitumor immunity, and inhibits tumor growth (Kortylewski et al., 2005). In some embodiments, RTA 408 and its polymorphic forms can be used to treat cancer, including, for example, prostate cancer. In some embodiments, RTA 408 and its polymorphic forms can be used in a combination therapy to treat cancer including, for example, prostate cancer. See, e.g., Example H below.

B. Multiple Sclerosis and Other Neurodegenerative Conditions

In some embodiments, RTA 408, the polymorphic forms, and the methods of this invention may be used for treating patients for multiple sclerosis (MS) or other neurodegenerative conditions such as Alzheimer's disease, Parkinson's disease, or amyotrophic lateral sclerosis. MS is known to be an inflammatory condition of the central nervous system (Williams et al., 1994; Merrill and Benvenist, 1996; Genain and Nauser, 1997). Based on several investigations, evidence suggests that inflammatory, oxidative, and/or immune mechanisms are involved in the pathogenesis of Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and MS (Bagasra et al., 1995; McGeer and McGeer, 1995; Simonian and Coyle, 1996; Kaltschmidt et al., 1997). Epidemiologic data indicate that chronic use of NSAIDs which block synthesis of prostaglandins from arachidonate, markedly lowers the risk for development of AD (McGeer et al., 1996; Stewart et al., 1997). Thus, agents that block formation of NO and prostaglandins, may be used in approaches to prevent and treat neurodegenerative diseases. Successful therapeutic candidates for treating such a disease typically require an ability to penetrate the blood-brain barrier. See, for example, U.S. Patent Publication 2009/0060873, which is incorporated by reference herein.

C. Neuroinflammation

In some embodiments, RTA 408, the polymorphic forms, and methods of this invention may be used for treating patients with neuroinflammation. Neuroinflammation encapsulates the idea that microglial and astrocytic responses and actions in the central nervous system have a fundamentally inflammation-like character, and that these responses are central to the pathogenesis and progression of a wide variety of neurological disorders. These ideas have been extended from Alzheimer's disease to other neurodegenerative diseases (Eikelenboom et al., 2002; Ishizawa and Dickson, 2001), to ischemic/toxic diseases (Gehrmann et al., 1995; Touzani et al., 1999), to tumor biology (Graeber et al., 2002) and even to normal brain development. Neuroinflammation incorporates a wide spectrum of complex cellular responses that include activation of microglia and astrocytes and induction of cytokines, chemokines, complement proteins, acute phase proteins, oxidative injury, and related molecular processes, and the events may have detrimental effects on neuronal function, leading to neuronal injury, further glial activation, and ultimately neurodegeneration.

D. Renal Diseases

In some embodiments, RTA 408, as well as polymorphic forms thereof, may be used for treating patients with renal diseases and disorders, including renal failure and chronic kidney disease (CKD), based, for example, on the methods taught by U.S. Pat. No. 8,129,429, which is incorporated by reference herein. Renal failure, resulting in inadequate clearance of metabolic waste products from the blood and abnormal concentrations of electrolytes in the blood, is a significant medical problem throughout the world, especially in developed countries. Diabetes and hypertension are among the most important causes of chronic renal failure, also known as chronic kidney disease (CKD), but it is also associated with other conditions such as lupus. Acute renal failure may arise from exposure to certain drugs (e.g., acetaminophen) or toxic chemicals, or from ischemia-reperfusion injury associated with shock or surgical procedures such as transplantation, and may result in chronic renal failure. In many patients, renal failure advances to a stage in which the patient requires regular dialysis or kidney transplantation to continue living. Both of these procedures are highly invasive and associated with significant side effects and quality of life issues. Although there are effective treatments for some complications of renal failure, such as hyperparathyroidism and hyperphosphatemia, no available treatment has been shown to halt or reverse the underlying progression of renal failure. Thus, agents that can improve compromised renal function would represent a significant advance in the treatment of renal failure.

Inflammation contributes significantly to the pathology of CKD. There is also a strong mechanistic link between oxidative stress and renal dysfunction. The NF-κB signaling pathway plays an important role in the progression of CKD as NF-κB regulates the transcription of MCP-1, a chemokine that is responsible for the recruitment of monocytes/macrophages resulting in an inflammatory response that ultimately injures the kidney (Wardle, 2001). The Keap1/Nrf2/ARE pathway controls the transcription of several genes encoding antioxidant enzymes, including heme oxygenase-1 (HO-1). Ablation of the Nrf2 gene in female mice results in the development of lupus-like glomerular nephritis (Yoh et al., 2001). Furthermore, several studies have demonstrated that HO-1 expression is induced in response to renal damage and inflammation and that this enzyme and its products—bilirubin and carbon monoxide—play a protective role in the kidney (Nath et al., 2006).

Acute kidney injury (AKI) can occur following ischemia-reperfusion, treatment with certain pharmacological agents, such as cisplatin and rapamycin, and intravenous injection of radiocontrast media used in medical imaging. As in CKD, inflammation and oxidative stress contribute to the pathology of AKI. The molecular mechanisms underlying radiocontrast-induced nephropathy (RCN) are not well understood; however, it is likely that a combination of events including prolonged vasoconstriction, impaired kidney autoregulation, and direct toxicity of the contrast media all contribute to renal failure (Tumlin et al., 2006). Vasoconstriction results in decreased renal blood flow and causes ischemia-reperfusion and the production of reactive oxygen species. HO-1 is strongly induced under these conditions and has been demonstrated to prevent ischemia-reperfusion injury in several different organs, including the kidney (Nath et al., 2006). Specifically, induction of HO-1 has been shown to be protective in a rat model of RCN (Goodman et al., 2007). Reperfusion also induces an inflammatory response, in part though activation of NF-κB signaling (Nichols, 2004). Targeting NF-κB has been proposed as a therapeutic strategy to prevent organ damage (Zingarelli et al., 2003).

E. Cardiovascular Disease

In some embodiments, RTA 408, the polymorphic forms and methods of this invention may be used for treating patients with cardiovascular disease. The etiology of CV disease is complex, but the majority of causes are related to inadequate or completely disrupted supply of blood to a critical organ or tissue. Frequently such a condition arises from the rupture of one or more atherosclerotic plaques, which leads to the formation of a thrombus that blocks blood flow in a critical vessel.

In some incidences, atherosclerosis may be so extensive in critical blood vessels that stenosis (narrowing of the arteries) develops and blood flow to critical organs (including the heart) is chronically insufficient. Such chronic ischemia can lead to end-organ damage of many kinds, including the cardiac hypertrophy associated with congestive heart failure.

Atherosclerosis, the underlying defect leading to many forms of cardiovascular disease, occurs when a physical defect or injury to the lining (endothelium) of an artery triggers an inflammatory response involving the proliferation of vascular smooth muscle cells and the infiltration of leukocytes into the affected area. Ultimately, a complicated lesion known as an atherosclerotic plaque may form, composed of the above-mentioned cells combined with deposits of cholesterol-bearing lipoproteins and other materials (e.g., Hansson et al., 2006). Despite the significant benefits offered by current therapeutic treatments, mortality from cardiovascular disease remains high and significant unmet needs in the treatment of cardiovascular disease remain.

Induction of HO-1 has been shown to be beneficial in a variety of models of cardiovascular disease, and low levels of HO-1 expression have been clinically correlated with elevated risk of CV disease. RTA 408, the polymorphic forms and methods of the invention, therefore, may be used in treating or preventing a variety of cardiovascular disorders including but not limited to atherosclerosis, hypertension, myocardial infarction, chronic heart failure, stroke, subarachnoid hemorrhage, and restenosis. In some embodiments, RTA 408, the polymorphic forms and methods of the invention may be used as a combination therapy with other known cardiovascular therapies such as but not limited to anticoagulants, thrombolytics, streptokinase, tissue plasminogen activators, surgery, coronary artery bypass grafting, balloon angioplasty, the use of stents, drugs which inhibit cell proliferation, or drugs which lower cholesterol levels.

F. Diabetes

In some embodiments, RTA 408, as well as polymorphic forms thereof, may be used for treating patients with diabetes, based, for example, on the methods taught by U.S. Pat. No. 8,129,429, which is incorporated by reference herein. Diabetes is a complex disease characterized by the body's failure to regulate circulating levels of glucose. This failure may result from a lack of insulin, a peptide hormone that regulates both the production and absorption of glucose in various tissues. Deficient insulin compromises the ability of muscle, fat, and other tissues to absorb glucose properly, leading to hyperglycemia (abnormally high levels of glucose in the blood). Most commonly, such insulin deficiency results from inadequate production in the islet cells of the pancreas. In the majority of cases this arises from autoimmune destruction of these cells, a condition known as type 1 or juvenile-onset diabetes, but may also be due to physical trauma or some other cause.

Diabetes may also arise when muscle and fat cells become less responsive to insulin and do not absorb glucose properly, resulting in hyperglycemia. This phenomenon is known as insulin resistance, and the resulting condition is known as type 2 diabetes. Type 2 diabetes, the most common type, is highly associated with obesity and hypertension. Obesity is associated with an inflammatory state of adipose tissue that is thought to play a major role in the development of insulin resistance (e.g., Hotamisligil, 2006; Guilherme et al., 2008).

Diabetes is associated with damage to many tissues, largely because hyperglycemia (and hypoglycemia, which can result from excessive or poorly timed doses of insulin) is a significant source of oxidative stress. Because of their ability to protect against oxidative stress, particularly by the induction of HO-1 expression, RTA 408, the polymorphic forms, and methods of the current invention may be used in treatments for many complications of diabetes. As noted above (Cai et al., 2005), chronic inflammation and oxidative stress in the liver are suspected to be primary contributing factors in the development of type 2 diabetes. Furthermore, PPAR_(γ) agonists such as thiazolidinediones are capable of reducing insulin resistance and are known to be effective treatments for type 2 diabetes. In some embodiments, RTA 408, the polymorphic forms, and methods of the current invention may be used as combination therapies with PPAR_(γ), agonists such as thiazolidinediones.

G. Arthritis

In some embodiments, RTA 408, the polymorphic forms, and methods of this invention may be used for treating patients with a form of arthritis. In some embodiments, the forms of arthritis that could be treated with RTA 408 and the polymorphic forms of this invention are rheumatoid arthritis (RA), psoriatic arthritis (PsA), spondyloarthropathies (SpAs) including ankylosing spondylitis (AS), reactive arthritis (ReA), and enteropathic arthritis (EA), juvenile rheumatoid arthritis (JRA), and early inflammatory arthritis.

For rheumatoid arthritis, the first signs typically appear in the synovial lining layer, with proliferation of synovial fibroblasts and their attachment to the articular surface at the joint margin (Lipsky, 1998). Subsequently, macrophages, T cells and other inflammatory cells are recruited into the joint, where they produce a number of mediators, including the cytokines interleukin-1 (IL-1), which contributes to the chronic sequelae leading to bone and cartilage destruction, and tumor necrosis factor (TNF-α), which plays a role in inflammation (Dinarello, 1998; Arend and Dayer, 1995; van den Berg, 2001). The concentration of IL-1 in plasma is significantly higher in patients with RA than in healthy individuals and, notably, plasma IL-1 levels correlate with RA disease activity (Eastgate et al., 1988). Moreover, synovial fluid levels of IL-1 are correlated with various radiographic and histologic features of RA (Kahle et al., 1992; Rooney et al., 1990).

Other forms of arthritis include psoriatic arthritis (PsA), which is a chronic inflammatory arthropathy characterized by the association of arthritis and psoriasis. Studies have revealed that PsA shares a number of genetic, pathogenic and clinical features with other spondyloarthropathies (SpAs), a group of diseases that comprise ankylosing spondylitis, reactive arthritis and enteropathic arthritis (Wright, 1979). The notion that PsA belongs to the SpA group has recently gained further support from imaging studies demonstrating widespread enthesitis in PsA but not RA (McGonagle et al., 1999; McGonagle et al., 1998). More specifically, enthesitis has been postulated to be one of the earliest events occurring in the SpAs, leading to bone remodeling and ankylosis in the spine, as well as to articular synovitis when the inflamed entheses are close to peripheral joints. Increased amounts of TNF-α have been reported in both psoriatic skin (Ettehadi et al., 1994) and synovial fluid (Partsch et al., 1997). Recent trials have shown a positive benefit of anti-TNF treatment in both PsA (Mease et al., 2000) and ankylosing spondylitis (Brandt et al., 2000).

Juvenile rheumatoid arthritis (JRA), a term for the most prevalent form of arthritis in children, is applied to a family of illnesses characterized by chronic inflammation and hypertrophy of the synovial membranes. The term overlaps, but is not completely synonymous, with the family of illnesses referred to as juvenile chronic arthritis and/or juvenile idiopathic arthritis in Europe.

Polyarticular JRA is a distinct clinical subtype characterized by inflammation and synovial proliferation in multiple joints (four or more), including the small joints of the hands (Jarvis, 2002). This subtype of JRA may be severe, because of both its multiple joint involvement and its capacity to progress rapidly over time. Although clinically distinct, polyarticular JRA is not homogeneous, and patients vary in disease manifestations, age of onset, prognosis, and therapeutic response. These differences very likely reflect a spectrum of variation in the nature of the immune and inflammatory attack that can occur in this disease (Jarvis, 1998).

Ankylosing spondylitis (AS) is a disease subset within a broader disease classification of spondyloarthropathy. Patients affected with the various subsets of spondyloarthropathy have disease etiologies that are often very different, ranging from bacterial infections to inheritance. Yet, in all subgroups, the end result of the disease process is axial arthritis.

AS is a chronic systemic inflammatory rheumatic disorder of the axial skeleton with or without extraskeletal manifestations. Sacroiliac joints and the spine are primarily affected, but hip and shoulder joints, and less commonly peripheral joints or certain extra-articular structures such as the eye, vasculature, nervous system, and gastrointestinal system may also be involved. The disease's etiology is not yet fully understood (Wordsworth, 1995; Calin and Taurog, 1998). The etiology is strongly associated with the major histocompatibility class I (MHC I) HLA-B27 allele (Calin and Taurog, 1998). AS affects individuals in the prime of their life and is feared because of its potential to cause chronic pain and irreversible damage of tendons, ligaments, joints, and bones (Brewerton et al., 1973a; Brewerton et al., 1973b; Schlosstein et al., 1973).

H. Ulcerative Colitis

In some embodiments, RTA 408, the polymorphic forms and methods of this invention may be used for treating patients with ulcerative colitis. Ulcerative colitis is a disease that causes inflammation and sores, called ulcers, in the lining of the large intestine. The inflammation usually occurs in the rectum and lower part of the colon, but it may affect the entire colon. Ulcerative colitis may also be called colitis or proctitis. The inflammation makes the colon empty frequently, causing diarrhea. Ulcers form in places where the inflammation has killed the cells lining the colon and the ulcers bleed and produce pus.

Ulcerative colitis is an inflammatory bowel disease (IBD), the general name for diseases that cause inflammation in the small intestine and colon. Ulcerative colitis can be difficult to diagnose because its symptoms are similar to other intestinal disorders and to another type of IBD, Crohn's disease. Crohn's disease differs from ulcerative colitis because it causes inflammation deeper within the intestinal wall. Also, Crohn's disease usually occurs in the small intestine, although the disease can also occur in the mouth, esophagus, stomach, duodenum, large intestine, appendix, and anus.

I. Crohn's Disease

In some embodiments, RTA 408, the polymorphic forms, and methods of this invention may be used for treating patients with Crohn's disease. Crohn's disease symptoms include intestinal inflammation and the development of intestinal stenosis and fistulas; neuropathy often accompanies these symptoms. Anti-inflammatory drugs, such as 5-aminosalicylates (e.g., mesalamine) or corticosteroids, are typically prescribed, but are not always effective (reviewed in Botoman et al., 1998). Immunosuppression with cyclosporine is sometimes beneficial for patients resistant to or intolerant of corticosteroids (Brynskov et al., 1989).

In active cases of Crohn's disease, elevated concentrations of TNF-α and IL-6 are secreted into the blood circulation, and TNF-α, IL-1, IL-6, and IL-8 are produced in excess locally by mucosal cells (id.; Funakoshi et al., 1998). These cytokines can have far-ranging effects on physiological systems including bone development, hematopoiesis, and liver, thyroid, and neuropsychiatric function. Also, an imbalance of the IL-1β/IL-1ra ratio, in favor of pro-inflammatory IL-1β, has been observed in patients with Crohn's disease (Rogler and Andus, 1998; Saiki et al., 1998; Dionne et al., 1998; but see Kuboyama, 1998).

Treatments that have been proposed for Crohn's disease include the use of various cytokine antagonists (e.g., IL-1ra), inhibitors (e.g., of IL-1β converting enzyme and antioxidants) and anti-cytokine antibodies (Rogler and Andus, 1998; van Hogezand and Verspaget, 1998; Reimund et al., 1998; Lugering et al., 1998; McAlindon et al., 1998). In particular, monoclonal antibodies against TNF-α have been tried with some success in the treatment of Crohn's disease (Targan et al., 1997; Stack et al., 1997; van Dullemen et al., 1995). These compounds may be used in combination therapy with RTA 408, the polymorphic forms, and methods of the present disclosure.

J. Systemic Lupus Erythematosus

In some embodiments, RTA 408, the polymorphic forms and methods of this invention may be used for treating patients with SLE. Systemic lupus erythematosus (SLE) is an autoimmune rheumatic disease characterized by deposition in tissues of autoantibodies and immune complexes leading to tissue injury (Kotzin, 1996). In contrast to autoimmune diseases, such as MS and type 1 diabetes mellitus, SLE potentially involves multiple organ systems directly, and its clinical manifestations are diverse and variable (reviewed by Kotzin and O'Dell, 1995). For example, some patients may demonstrate primarily skin rash and joint pain, show spontaneous remissions, and require little medication. At the other end of the spectrum are patients who demonstrate severe and progressive kidney involvement that requires therapy with high doses of steroids and cytotoxic drugs such as cyclophosphamide (Kotzin, 1996).

One of the antibodies produced by SLE, IgG anti-dsDNA, plays a major role in the development of lupus glomerulonephritis (GN) (Hahn and Tsao, 1993; Ohnishi et al., 1994). Glomerulonephritis is a serious condition in which the capillary walls of the kidney's blood purifying glomeruli become thickened by accretions on the epithelial side of glomerular basement membranes. The disease is often chronic and progressive and may lead to eventual renal failure.

K. Irritable Bowel Syndrome

In some embodiments, RTA 408, the polymorphic forms, and methods of this invention may be used for treating patients with irritable bowel syndrome (IBS). IBS is a functional disorder characterized by abdominal pain and altered bowel habits. This syndrome may begin in young adulthood and can be associated with significant disability. This syndrome is not a homogeneous disorder. Rather, subtypes of IBS have been described on the basis of the predominant symptom—diarrhea, constipation, or pain. In the absence of “alarm” symptoms, such as fever, weight loss, and gastrointestinal bleeding, a limited workup is needed.

Increasingly, evidence for the origins of IBS suggests a relationship between infectious enteritis and subsequent development of IBS. Inflammatory cytokines may play a role. In a survey of patients with a history of confirmed bacterial gastroenteritis (Neal et al., 1997), 25% reported persistent alteration of bowel habits. Persistence of symptoms may be due to psychological stress at the time of acute infection (Gwee et al., 1999).

Recent data suggest that bacterial overgrowth in the small intestine may also have a role in IBS symptoms. In one study (Pimentel et al., 2000), 157 (78%) of 202 IBS patients referred for hydrogen breath testing had test findings that were positive for bacterial overgrowth. Of the 47 subjects who had follow-up testing, 25 (53%) reported improvement in symptoms (i.e., abdominal pain and diarrhea) with antibiotic treatment.

L. Sjögren's Syndrome

In some embodiments, RTA 408, the polymorphic forms, and methods of this invention may be used for treating patients with Sjögren's syndrome. Primary Sjögren's syndrome (SS) is a chronic, slowly progressive, systemic autoimmune disease, which affects predominantly middle-aged women (female-to-male ratio 9:1), although it can be seen in all ages including childhood (Jonsson et al., 2002). The disease is characterized by lymphocytic infiltration and destruction of the exocrine glands, which are infiltrated by mononuclear cells including CD4+, CD8+ lymphocytes, and B-cells (Jonsson et al., 2002). In addition, extraglandular (systemic) manifestations are seen in one-third of patients (Jonsson et al., 2001).

In other systemic autoimmune diseases, such as RA, factors critical for ectopic germinal centers (GCs) have been identified. Rheumatoid synovial tissues with GCs were shown to produce chemokines CXCL13, CCL21, and lymphotoxin (LT)-β (detected on follicular center and mantle zone B cells). Multivariate regression analysis of these analytes identified CXCL13 and LT-β as the solitary cytokines predicting GCs in rheumatoid synovitis (Weyand and Goronzy, 2003). Recently CXCL13 and CXCR5 in salivary glands has been shown to play an essential role in the inflammatory process by recruiting B and T cells, therefore contributing to lymphoid neogenesis and ectopic GC formation in SS (Salomonsson et al., 2002).

M. Psoriasis

In some embodiments, RTA 408, the polymorphic forms, and methods of this invention may be used for treating patients with psoriasis. Psoriasis is a chronic skin disease of scaling and inflammation that affects 2 to 2.6 percent of the United States population, or between 5.8 and 7.5 million people. Psoriasis occurs when skin cells quickly rise from their origin below the surface of the skin and pile up on the surface before they have a chance to mature. Usually this movement (also called turnover) takes about a month, but in psoriasis turnover may occur in only a few days. In its typical form, psoriasis results in patches of thick, red (inflamed) skin covered with silvery scales. These patches, which are sometimes referred to as plaques, usually itch or feel sore. The plaques most often occur on the elbows, knees, other parts of the legs, scalp, lower back, face, palms, and soles of the feet, but they can occur on skin anywhere on the body. The disease may also affect the fingernails, the toenails, and the soft tissues of the genitals and inside the mouth.

Psoriasis is a skin disorder driven by the immune system, especially involving a type of white blood cell called a T cell. Normally, T cells help protect the body against infection and disease. In the case of psoriasis, T cells are put into action by mistake and become so active that they trigger other immune responses, which lead to inflammation and to rapid turnover of skin cells.

N. Infectious Diseases

In some embodiments, RTA 408, the polymorphic forms, and methods of the present disclosure may be useful in the treatment of infectious diseases, including viral and bacterial infections. As noted above, such infections may be associated with severe localized or systemic inflammatory responses. For example, influenza may cause severe inflammation of the lung and bacterial infection can cause the systemic hyperinflammatory response, including the excessive production of multiple inflammatory cytokines, which is the hallmark of sepsis. In addition, compounds of the invention may be useful in directly inhibiting the replication of viral pathogens. Previous studies have demonstrated that related compounds such as CDDO can inhibit the replication of HIV in macrophages (Vazquez et al., 2005). Other studies have indicated that inhibition of NF-κB signaling may inhibit influenza virus replication, and that cyclopentenone prostaglandins may inhibit viral replication (e.g., Mazur et al., 2007; Pica et al., 2000).

The present invention relates to the treatment or prevention of each of the diseases/disorders/conditions referred to above in section IV using the compound RTA 408 or a pharmaceutically acceptable salt thereof, or a polymorphic form of that compound (such as, e.g., any one of the polymorphic forms described herein above or below), or a pharmaceutical composition comprising any of the aforementioned entities and a pharmaceutically acceptable carrier (including, e.g., the pharmaceutical compositions described above).

V. PHARMACEUTICAL FORMULATIONS AND ROUTES OF ADMINISTRATION

RTA 408 may be administered by a variety of methods, e.g., orally or by injection (e.g., subcutaneous, intravenous, intraperitoneal, etc.). Depending on the route of administration, the active compounds may be coated in a material to protect the compound from the action of acids and other natural conditions which may inactivate the compound. They may also be administered by continuous perfusion/infusion of a disease or wound site.

To administer RTA 408 by other than parenteral administration, it may be necessary to coat the compound with, or co-administer the compound with, a material to prevent its inactivation. For example, the therapeutic compound may be administered to a patient in an appropriate carrier, for example, liposomes, or a diluent. Pharmaceutically acceptable diluents include saline and aqueous buffer solutions. Liposomes include water-in-oil-in-water CGF emulsions as well as conventional liposomes (Strejan et al., 1984).

RTA 408 may also be administered parenterally, intraperitoneally, intraspinally, or intracerebrally. Dispersions can be prepared in glycerol, liquid polyethylene glycols, and mixtures thereof and in oils. Under ordinary conditions of storage and use, these preparations may contain a preservative to prevent the growth of microorganisms.

Sterile injectable solutions can be prepared by incorporating RTA 408 in the required amount in an appropriate solvent with one or a combination of ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the therapeutic compound into a sterile carrier that contains a basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and freeze-drying, which yields a powder of the active ingredient (i.e., the therapeutic compound) plus any additional desired ingredient from a previously sterile-filtered solution thereof.

RTA 408 may be rendered fully amorphous using a direct spray drying procedure. RTA 408 can be orally administered, for example, with an inert diluent or an assimilable edible carrier. The therapeutic compound and other ingredients may also be enclosed in a hard or soft shell gelatin capsule, compressed into tablets, or incorporated directly into the patient's diet. For oral therapeutic administration, the therapeutic compound may be incorporated, for example, with excipients and used in the form of ingestible tablets, buccal tablets, troches, capsules including hard or soft capsules, elixirs, emulsions, solid dispersions, suspensions, syrups, wafers, and the like. The percentage of the therapeutic compound in the compositions and preparations may, of course, be varied. The amount of the therapeutic compound in such therapeutically useful compositions is such that a suitable dosage will be obtained.

It is especially advantageous to formulate parenteral compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form as used herein refers to physically discrete units suited as unitary dosages for the patients to be treated, each unit containing a predetermined quantity of therapeutic compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. The specification for the dosage unit forms of the invention are dictated by and directly dependent on (a) the unique characteristics of the therapeutic compound and the particular therapeutic effect to be achieved, and (b) the limitations inherent in the art of compounding such a therapeutic compound for the treatment of a selected condition in a patient.

RTA 408 may also be administered topically to the skin, eye, or mucosa. In some embodiments, the compound may be prepared in a lotion, cream, gel, oil, ointment, salve, solution, suspension, or emulsion. Alternatively, if local delivery to the lungs is desired the therapeutic compound may be administered by inhalation in a dry-powder or aerosol formulation.

RTA 408 will typically be administered at a therapeutically effective dosage sufficient to treat a condition associated with a given patient. For example, the efficacy of a compound can be evaluated in an animal model system that may be predictive of efficacy in treating the disease in humans, such as the model systems shown in the examples and drawings.

The actual dosage amount of RTA 408 or composition comprising RTA 408 administered to a patient may be determined by physical and physiological factors, such as age, sex, body weight, severity of condition, the type of disease being treated, previous or concurrent therapeutic interventions, idiopathy of the patient, and the route of administration. These factors may be determined by a skilled artisan. The practitioner responsible for administration will typically determine the concentration of active ingredient(s) in a composition and appropriate dose(s) for the individual patient. The dosage may be adjusted by the individual physician in the event of any complication.

An effective amount typically will vary from about 0.001 mg/kg to about 1000 mg/kg, from about 0.01 mg/kg to about 750 mg/kg, from about 100 mg/kg to about 500 mg/kg, from about 1.0 mg/kg to about 250 mg/kg, from about 10.0 mg/kg to about 150 mg/kg in one or more dose administrations daily, for one or several days (depending of course of the mode of administration and the factors discussed above). Other suitable dose ranges include 1 mg to 10000 mg per day, 100 mg to 10000 mg per day, 500 mg to 10000 mg per day, and 500 mg to 1000 mg per day. In some particular embodiments, the amount is less than 10,000 mg per day with a range of 750 mg to 9000 mg per day.

The effective amount may be less than 1 mg/kg/day, less than 500 mg/kg/day, less than 250 mg/kg/day, less than 100 mg/kg/day, less than 50 mg/kg/day, less than 25 mg/kg/day, or less than 10 mg/kg/day. It may alternatively be in the range of 1 mg/kg/day to 200 mg/kg/day. In some embodiments, the amount could be 10, 30, 100, or 150 mg/kg formulated as a suspension in sesame oil as described below in Example C1. In some embodiments, the amount could be 3, 10, 30 or 100 mg/kg administered daily via oral gavage as described below in Examples C2 and C3. In some embodiments, the amount could be 10, 30, or 100 mg/kg administered orally as described below in Example C6. For example, regarding treatment of diabetic patients, the unit dosage may be an amount that reduces blood glucose by at least 40% as compared to an untreated patient. In another embodiment, the unit dosage is an amount that reduces blood glucose to a level that is ±10% of the blood glucose level of a non-diabetic patient.

In other non-limiting examples, a dose may also comprise from about 1 μg/kg body weight, about 5 μg/kg body weight, about 10 μg/kg body weight, about 50 μg/kg body weight, about 100 μg/kg body weight, about 200 μg/kg body weight, about 350 μg/kg body weight, about 500 μg/kg body weight, about 1 mg/kg body weight, about 5 mg/kg body weight, about 10 mg/kg body weight, about 50 mg/kg body weight, about 100 mg/kg body weight, about 200 mg/kg body weight, about 350 mg/kg body weight, about 500 mg/kg body weight, to about 1000 mg/kg body weight or more per administration, and any range derivable therein. In non-limiting examples of a derivable range from the numbers listed herein, a range of about 5 mg/kg body weight to about 100 mg/kg body weight, about 5 μg/kg body weight to about 500 mg/kg body weight, etc., can be administered, based on the numbers described above.

In certain embodiments, a pharmaceutical composition of the present disclosure may comprise, for example, at least about 0.01% of RTA 408. In other embodiments, RTA 408 may comprise between about 0.01% to about 75% of the weight of the unit, or between about 0.01% to about 5%, for example, and any range derivable therein. In some embodiments, RTA 408 may be used in a formulation such as a suspension in sesame oil of 0.01%, 0.1%, or 1% as described below in Examples F and G. In some embodiments, RTA 408 may be formulated for topical administration to the skin or eye, using a pharmaceutically suitable carrier or as a suspension, emulsion, or solution in concentrations ranging from about 0.01% to 10%. In some embodiments the concentration ranges from about 0.1% to about 5%. The optimal concentration may vary depending upon the target organ, the specific preparation, and the condition to be treated.

Single or multiple doses of the agent comprising RTA 408 are contemplated. Desired time intervals for delivery of multiple doses can be determined by one of ordinary skill in the art employing no more than routine experimentation. As an example, patients may be administered two doses daily at approximately 12 hour intervals. In some embodiments, the agent is administered once a day. The agent(s) may be administered on a routine schedule. As used herein a routine schedule refers to a predetermined designated period of time. The routine schedule may encompass periods of time that are identical or that differ in length, as long as the schedule is predetermined. For instance, the routine schedule may involve administration twice a day, every day, every two days, every three days, every four days, every five days, every six days, a weekly basis, a monthly basis, or any set number of days or weeks there-between. Alternatively, the predetermined routine schedule may involve administration on a twice daily basis for the first week, followed by a daily basis for several months, etc. In other embodiments, the invention provides that the agent(s) may be taken orally and that the timing of which is or is not dependent upon food intake. Thus, for example, the agent can be taken every morning and/or every evening, regardless of when the patient has eaten or will eat.

VI. COMBINATION THERAPY

In addition to being used as a monotherapy, RTA 408 and the polymorphic forms described in the present invention may also find use in combination therapies. Effective combination therapy may be achieved with a single composition or pharmacological formulation that includes both agents, or with two distinct compositions or formulations, administered at the same time, wherein one composition includes RTA 408 or its polymorphic forms, and the other includes the second agent(s). The other therapeutic modality may be administered before, concurrently with, or following administration of RTA 408 or its polymorphic forms. The therapy using RTA 408 or its polymorphic forms may precede or follow administration of the other agent(s) by intervals ranging from minutes to weeks. In embodiments where the other agent and RTA 408 or its polymorphic forms are administered separately, one would generally ensure that a significant period of time did not expire between the time of each delivery, such that each agent would still be able to exert an advantageously combined effect. In such instances, it is contemplated that one would typically administer RTA 408 or the polymorphic forms and the other therapeutic agent within about 12-24 hours of each other and, more preferably, within about 6-12 hours of each other, with a delay time of only about 12 hours being most preferred. In some situations, it may be desirable to extend the time period for treatment significantly, however, where several days (2, 3, 4, 5, 6 or 7) to several weeks (1, 2, 3, 4, 5, 6, 7 or 8) lapse between the respective administrations.

It also is conceivable that more than one administration of RTA 408 or its polymorphic forms, or the other agent will be desired. In this regard, various combinations may be employed. By way of illustration, where RTA 408 or its polymorphic forms is “A” and the other agent is “B”, the following permutations based on 3 and 4 total administrations are exemplary:

-   -   A/B/A B/A/B B/B/A A/A/B B/A/A A/B/B B/B/B/A B/B/A/B A/A/B/B         A/B/A/B A/B/B/A B/B/A/A B/A/B/A B/A/A/B B/B/B/A A/A/A/B B/A/A/A         A/B/A/A A/A/B/A A/B/B/B B/A/B/B B/B/A/B

Other combinations are likewise contemplated. Non-limiting examples of pharmacological agents that may be used in the present invention include any pharmacological agent known to be of benefit in the treatment of a cancer. In some embodiments, combinations of RTA 408 or its polymorphic forms with a cancer targeting immunotherapy, gene therapy, radiotherapy, chemotherapeutic agent, or surgery are contemplated. Also contemplated is a combination of RTA 408 or its polymorphic forms with more than one of the above mentioned methods including more than one type of a specific therapy. In some embodiments, the immunotherapy can be other cancer targeting antibodies such as but not limited to trastuzumab (HEPCEPTIN®), alemtuzumab (CAMPATH®), bevacizumab (AVASTIN®), cetuximab (ERIBITUS®), and panitumumab (VECTIBIX®) or conjugated antibodies such as ibritumomab tiuxetan (ZEVALIN®), tositumomab (BEXXAR®), brentuximab vedotin (ADCETRIS®), ado-trastuzumab emtansine (KADCYLA™), or denileukin dititox (ONTAK®). Furthermore, in some embodiments, RTA 408 or its polymorphic forms are envisioned to be used in combination therapies with dendritic cell-based immunotherapies such as Sipuleucel-T (PROVENGE®) or adoptive T-cell immunotherapies.

Furthermore, it is contemplated that RTA 408 or its polymorphic forms are used in combination with a chemotherapeutic agent such as but not limited to anthracyclines, taxanes, methotrexate, mitoxantrone, estramustine, doxorubicin, etoposide, vinblastine, carboplatin, vinorelbine, 5-fluorouracil, cisplatin, topotecan, ifosfamide, cyclophosphamide, epirubicin, gemcitabine, vinorelbine, irinotecan, etoposide, vinblastine, pemetrexed, melphalan, capecitabine, and oxaliplatin. In some embodiments, RTA 408 or its polymorphic forms are used in combination with radiation therapy including but not limited to the use of ionizing radiation. In some embodiments, the effects of the cancer therapeutic agent are synergistically enhanced through administration with RTA 408 and its polymorphic forms. In some embodiments, combination therapies which included RTA 408 are used to treat cancer including for example, prostate cancer. See, e.g., Example H below.

In some embodiments, the methods may further comprise (1) contacting a tumor cell with the compound prior to contacting the tumor cell with the second chemotherapeutic agent, (2) contacting a tumor cell with the second chemotherapeutic agent prior to contacting the tumor cell with the compound, or (3) contacting a tumor cell with the compound and the second chemotherapeutic agent at the same time. The second chemotherapeutic agent may, in certain embodiments, be an antibiotic, anti-inflammatory, anti-neoplastic, anti-proliferative, anti-viral, immunomodulatory, or immunosuppressive. In other embodiments, the second chemotherapeutic agent may be an alkylating agent, androgen receptor modulator, cytoskeletal disruptor, estrogen receptor modulator, histone-deacetylase inhibitor, HMG-CoA reductase inhibitor, prenyl-protein transferase inhibitor, retinoid receptor modulator, topoisomerase inhibitor, or tyrosine kinase inhibitor. In certain embodiments, the second chemotherapeutic agent is 5-azacitidine, 5-fluorouracil, 9-cis-retinoic acid, actinomycin D, alitretinoin, all-trans-retinoic acid, annamycin, axitinib, belinostat, bevacizumab, bexarotene, bosutinib, busulfan, capecitabine, carboplatin, carmustine, CD437, cediranib, cetuximab, chlorambucil, cisplatin, cyclophosphamide, cytarabine, dacarbazine, dasatinib, daunorubicin, decitabine, docetaxel, dolastatin-10, doxifluridine, doxorubicin, doxorubicin, epirubicin, erlotinib, etoposide, gefitinib, gemcitabine, gemtuzumab ozogamicin, hexamethylmelamine, idarubicin, ifosfamide, imatinib, irinotecan, isotretinoin, ixabepilone, lapatinib, LBH589, lomustine, mechlorethamine, melphalan, mercaptopurine, methotrexate, mitomycin, mitoxantrone, MS-275, neratinib, nilotinib, nitrosourea, oxaliplatin, paclitaxel, plicamycin, procarbazine, semaxanib, semustine, sodium butyrate, sodium phenylacetate, streptozotocin, suberoylanilide hydroxamic acid, sunitinib, tamoxifen, teniposide, thiopeta, tioguanine, topotecan, TRAIL, trastuzumab, tretinoin, trichostatin A, valproic acid, valrubicin, vandetanib, vinblastine, vincristine, vindesine, or vinorelbine.

Additionally, combination therapies for the treatment of cardiovascular disease utilizing RTA 408, polymorphic forms, and pharmaceutical compositions of the present disclosure are contemplated. For example, such methods may further comprise administering a pharmaceutically effective amount of one or more cardiovascular drugs in addition to RTA 408, polymorphic forms, and pharmaceutical compositions of the present disclosure. The cardiovascular drug may be but not limited to, for example, a cholesterol lowering drug, an anti-hyperlipidemic, a calcium channel blocker, an anti-hypertensive, or an HMG-CoA reductase inhibitor. In some embodiments, non-limiting examples of cardiovascular drugs include amlodipine, aspirin, ezetimibe, felodipine, lacidipine, lercanidipine, nicardipine, nifedipine, nimodipine, nisoldipine or nitrendipine. In other embodiments, other non-limiting examples of cardiovascular drugs include atenolol, bucindolol, carvedilol, clonidine, doxazosin, indoramin, labetalol, methyldopa, metoprolol, nadolol, oxprenolol, phenoxybenzamine, phentolamine, pindolol, prazosin, propranolol, terazosin, timolol or tolazoline. In other embodiments, the cardiovascular drug may be, for example, a statin, such as atorvastatin, cerivastatin, fluvastatin, lovastatin, mevastatin, pitavastatin, pravastatin, rosuvastatin or simvastatin.

VII. EXAMPLES

The following examples are included to demonstrate preferred embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent techniques discovered by the inventor to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.

A. Synthesis of RTA 408 (63415)

Compound 1:

To a solution of toluene (400 mL), RTA 401 (which can be prepared according to the methods taught, for example, by Honda, et al., 1998; Honda et al., 2000b; Honda et al., 2002; Yates et al., 2007; and U.S. Pat. Nos. 6,326,507 and 6,974,801, which are incorporated herein by reference) (20.0 g, 40.6 mmol) and Et₃N (17.0 mL, 122.0 mmol) were added into a reactor and cooled to 0° C. with stirring. Diphenyl phosphoryl azide (DPPA) (13.2 mL, 61.0 mmol) was added with stirring at 0° C. over 5 min and the mixture was continually stirred at room temperature overnight (HPLC-MS check shows no RTA 401 left). The reaction mixture was directly loaded on a silica gel column and purified by column chromatography (silica gel, 0% to 5% EtOAc in CH₂Cl₂) to give compound 1 (19.7 g, ˜94%, partially converted into compound 2) as a white foam.

Compound 2:

Compound 1 (19.7 g, ˜38.1 mmol) and benzene (250 mL) were added into a reactor and heated to 80° C. with stirring for 2 h (HPLC-MS check shows no compound 1 left). The reaction mixture was concentrated at reduced pressure to afford crude compound 2 as a solid residue, which was used for the next step without purification.

Compound 3:

Crude compound 2 (≦38.1 mmol) and CH₃CN (200 mL) were added into a reactor and cooled to 0° C. with stirring. HCl (12 N, 90 mL) was added at 0° C. over 1 min and the mixture was continually stirred at room temperature for 1 h (HPLC-MS check shows no compound 2 left). The reaction mixture was cooled to 0° C. and 10% NaOH (˜500 mL) was added with stirring. Then, saturated NaHCO₃ (1 L) was added with stirring. The aqueous phase was extracted by EtOAc (2×500 mL). The combined organic phase was washed by H₂O (200 mL), saturated NaCl (200 mL), dried over Na₂SO₄, and concentrated to afford crude compound 3 (16.62 g) as a light yellow foam, which was used for the next step without purification.

RTA 408:

Crude amine 3 (16.62 g, 35.9 mmol), CH₃CF₂CO₂H (4.7388 g, 43.1 mmol), and CH₂Cl₂ (360 mL) were added into a reactor with stirring at room temperature. Then, dicyclohexylcarbodiimide (DCC) (11.129 g, 53.9 mmol) and 4-(dimethylamino)-pyridine (DMAP) (1.65 g, 13.64 mmol) were added and the mixture was continually stirred at room temperature overnight (HPLC-MS check shows no compound 3 left). The reaction mixture was filtered to remove solid by-products and the filtrate was directly loaded on a silica gel column and purified by column chromatography (silica gel, 0% to 20% EtOAc in Hexanes) twice to give compound RTA 408 (16.347 g, 73% from RTA 401 over 4 steps) as a white foam: ¹H NMR (400 MHz, CD₃Cl) δ 8.04 (s, 1H), 6.00 (s, 1H), 5.94 (s, br, 1H), 3.01 (d, 1H, J=4.8 Hz), 2.75-2.82 (m, 1H), 1.92-2.18 (m, 4H), 1.69-1.85 (m, 7H), 1.53-1.64 (m, 1H), 1.60 (s, 3H), 1.50 (s, 3H), 1.42 (s, 3H), 1.11-1.38 (m, 3H), 1.27 (s, 3H), 1.18 (s, 3H), 1.06 (s, 3H), 1.04 (s, 3H), 0.92 (s, 3H); m/z 555 (M+1).

B. Pharmacodynamics

A summary of the in vitro and in vivo studies to evaluate the primary pharmacodynamic effects of RTA 408 is provided below.

1. Effects of RTA 408 on Keap1-Nrf2 and NF-κB in Vitro

Inhibition of IFNγ-induced NO production by AIMs is Nrf2-dependent (Dinkova-Kostova, 2005). RAW264.7 mouse macrophages were plated in 96-well plates at 30,000 cells/well in triplicated in RPMI 1640 supplemented with 0.5% FBS and incubated at 37° C. with 5% CO₂. On the next day, cells were pre-treated with DMSO (vehicle) or RTA 408 for 2 h, followed by treatment with 20 ng/mL of mouse IFNγ for 24 h. Nitrite (NO₂ ⁻) levels in the media were measured as a surrogate for nitric oxide using the Griess Reagent System (cat #G2930, Promega), according to the manufacturer's instructions, since nitrite is a primary, stable breakdown product of NO. Cell viability was assessed using the WST-1 Cell Proliferation Reagent (cat #11644807001, Roche Applied Science) according to the manufacturer's instructions. IC₅₀ values were determined based on the suppression of IFNγ-induced nitric oxide production normalized to cell viability. Treatment with RTA 408 resulted in a dose-dependent suppression of IFNγ-induced NO production, with an average IC₅₀ value of 3.8±1.2 nM. Results from a representative experiment are shown in FIG. 1. The IC₅₀ value for RTA 408 was found to be 45%-65% lower than the IC₅₀ values for compounds 63170 (8±3 nM), 63171 (6.9±0.6 nM), 63179 (11±2 nm), and 63189 (7±2 nM). 63170, 63171, 63179, and 63189 are compounds of the formulas:

2. Effect of RTA 408 on Nrf2 Target Genes

RTA 408 was tested in two different luciferase reporter assays to assess activation of the ARE. The first luciferase reporter tested was under the control of a single ARE derived from the promoter of the human NQO1 gene, which allows for quantitative assessment of the endogenous activity of the Nrf2 transcription factor in cultured mammalian cells. Expression of Firefly luciferase from NQO1-ARE luciferase reporter plasmid is controlled by binding of Nrf2 to a specific enhancer sequence corresponding to the antioxidant response element (ARE) that was identified in the promoter region of the human NADPH:quinone oxidoreductase 1 (NQO1) gene (Xie et al., 1995). The NQO1-ARE-luciferase reporter plasmid was constructed by inserting the human NQO 1-ARE (5′-CAGTCACAGTGACTCAGCAGAATCTG-3′) into the pLuc-MCS vector using HindIII/XhoI cloning sites (GenScript Corp., Piscataway, N.J.). The HuH-7 human hepatoma cell line, maintained in DMEM (Invitrogen) supplemented with 10% FBS and 100 U/mL (each) of penicillin and streptomycin, was transiently transfected using Lipofectamine 2000 (Invitrogen) with the NQO1-ARE luciferase reporter plasmid and the pRL-TK plasmid, which constitutively expresses Renilla luciferase and is used as an internal control for normalization of transfection levels. Thirty hours of transfection, cells were treated with RTA 408 for 18 h. Firefly and Renilla luciferase activity was assayed by Dual-Glo Luciferase Assay (cat # E2920, Promega), and the luminescence signal was measured on an L-Max II luminometer (Molecular Devices). Firefly luciferase activity was normalized to the Renilla activity, and fold induction over a vehicle control (DMSO) of normalized Firefly activity was calculated. FIG. 2 a shows a dose-dependent induction of luciferase activity by RTA 408 in this cell line. Values represent the average of three independent experiments. Twenty percent less RTA 408 (12 nM) than 63189 (14.9 nM) was required to increase transcription from the NQO1 ARE in HuH-7 cells by 2-fold. Likewise, 2.1-2.4 fold less RTA 408 than 63170 (25.2 nM) and 63179 (29.1 nM), respectively, was required to increase transcription from the NQO1 ARE in HuH-7 cells by 2-fold.

The effect of RTA 408 on luciferase reporter activation was also assessed in the AREc32 reporter cell line. This cell line is derived from human breast carcinoma MCF-7 cells and is stably transfected with a Firefly luciferase reporter gene under the transcriptional control of eight copies of the rat GSTA2 ARE sequence (Wang, et al., 2006, which is incorporated herein by reference). Following treatment with RTA 408 for 18 h, Firefly luciferase activity was measured using the ONE-Glo Luciferase Assay System (Promega, Catalog #E6110) according to the manufacturer's instructions. A dose-dependent response was observed in the AREc32 reporter cell line (FIG. 2 b). A ˜2-fold induction of luciferase activity was evident following treatment with 15.6 nM RTA 408 in both the NQO1-ARE and GSTA2-ARE reporter assay system. When looking at the results from the GSTA2-ARE (AREc32) luciferase activity study, the effects of 63415 (RTA 408) on GSTA2-ARE induction can be directly compared to that of RTA 402, 63170, 63171, 63179, and 63189 along with WST1 viability studies (FIGS. 3 a-f). Compared to the values of RTA 402, 63415 showed the quickest induction of GSTA2-ARE-mediated transcription of the five comparison compounds with a concentration of 93 nM needed to reach 4-fold induction in the luciferase reporter assay. All other compounds showed a similar induction only with much higher concentrations with 63170 needing a concentration of 171 nM, 63171 needing a concentration of 133 nM, 63179 needing a concentration of 303 nM and 63189 needing a concentration of 174 nM to achieve a 4 fold induction of luciferase activity. These values correspond to a 1.86 (63415), 3.40 (63170), 2.65 (63171), 6.05 (63179) and 3.47 (63189) fold increase in the amount of the active compound needed compared to RTA 402 to lead to the same amount of activity.

RTA 408 was also shown to increase transcript levels of known Nrf2 target genes in the HFL1 human fetal lung fibroblast and BEAS-2B human bronchial epithelial cell lines. HFL1 cells were cultured in F-12K media supplemented with 10% fetal bovine serum and 1% penicillin-streptomycin. BEAS-2B cells were cultured in DMEM/F-12 media supplemented with 10% fetal bovine serum and 1% penicillin-streptomycin. Cells were plated in 6-well dishes at a density of 2.5×10⁵ cells/well. The following day, cells were treated with DMSO (vehicle) or RTA 408 (7.8, 15.6, 31.3, 62.5, or 125 nM) for 18 h. Each well received the same amount of vehicle. Following treatment, media was removed and cells were harvested using RLT buffer (Qiagen). Lysates were homogenized using QIAShredder columns (Qiagen, Catalog #79654) and RNA was isolated using RNeasy Mini kits (Qiagen, Catalog #74104). For reverse transcription, RNA (1 μg) was combined with Oligo(dT)₁₂₋₁₈ primer and H₂O in a final volume of 23.25 pt. The mixture was heated to 70° C. for 10 min and then placed on ice. A master mix containing 8 μL 5× 1^(st) strand buffer, 2 μL 1 mg/ml BSA, 2 μL 20 mM DTT, 4 μL 5 mM dNTP mix, 0.25 μL RNaseOUT™ and 0.5 μL SUPERSCRIPT® II reverse transcriptase was added to the RNA mixture and incubated at 42° C. for 1 h. The reaction was inactivated by heating to 70° C. for 10 min. The reaction mixture was diluted 1:3 with H₂O prior to use in qPCR. 2.5 μL of the diluted reverse transcription reaction was combined with one set of PCR primers (0.36 μM final concentration), 2× iQ™ SYBR® Green Supermix (Bio-Rad, Catalog #170-8885) and H₂O to a final volume of 20 μL Sequences for PCR primers are as follows: Glutamate-cysteine ligase, modifier subunit (GCLM), forward primer 5′-GCTGTGGCTACTGCGGTATT-3′ (SEQ ID NO: 1) reverse primer 5′-ATCTGCCTCAATGACACCAT-3′ (SEQ ID NO: 2); Heme oxygenase-1 (HMOX1) forward primer 5′-TCCGATGGGTCCTTACACTC-3′ (SEQ ID NO: 3), reverse primer 5′-TAGGCTCCTTCCTCCTTTCC-3′ (SEQ ID NO: 4); NAD(P)H dehydrogenase, quinone 1 (NQO1) forward primer 5′-AAAACACTGCCCTCTTGTGG-3′ (SEQ ID NO: 5), reverse primer 5′-GTGCCAGTCAGCATCTGGTA-3′ (SEQ ID NO: 6); Ribosomal protein S9 (RPS9) forward primer 5′-GATGAGAAGGACCCCACGGCGTCTG-3′ (SEQ ID NO: 7), reverse primer 5′-GAGACAATCCAGCAGCCCAGGAGGG-3′ (SEQ ID NO: 8); Thioredoxin Reductase 1 (TXNRD1) forward primer 5′-ATTGCCACTGGTGAAAGACC-3′ (SEQ ID NO: 9), reverse primer 5′-ACCAATTTTGTTGGCCATGT-3′ (SEQ ID NO: 10). All primers had previously been validated for specificity and amplification efficiency. cDNA was amplified using the following cycle conditions: (95° C. for 3 min, 44 cycles of 95° C. for 30 sec, 60° C. for 15 sec, 72° C. for 15 sec, followed by a melt curve of 55° C. to 95° C. in increments of 0.5° C.). The relative abundance of each Nrf2 target gene was determined using the comparative C_(T) method (ΔΔC_(T)). PCR reactions were run in triplicate wells for each sample. Two independent experiments were performed using the conditions described above. Treatment of HFL1 lung fibroblasts with RTA 408 for 18 h resulted in increased expression of several Nrf2 target genes, including NQO1, HMOX1, GCLM, and TXNRD1, as measured by quantitative PCR (FIGS. 4 a-d). For all genes tested, induction by RTA 408 was dose-dependent and evident at concentrations as low as 15.6 nM. Treatment of BEAS-2B bronchial epithelial cells with RTA 408 for 18 h resulted in a similar dose-dependent increase of all Nrf2 target genes evaluated (FIGS. 5 a-d). RTA 408 also increased expression of Nrf2 target genes in normal human mesangial cells (nHMC), the mouse BV2 microglial cell line, and the human SH-SY5Y neuroblastoma cell line at similar concentrations.

Protein levels of Nrf2 targets NQO1 and HMOX1 were measured in SH-5Y5Y and BV-2 cells by Western blot following treatment with RTA 408. SH-SY5Y cells were plated in 6-well plates at a density of 4×10⁵ cells per well. BV-2 cells were plated in 6-well plates at a density of 2.5×10⁴ cells per well. Twenty-four (BV-2) or 48 (SH-SY5Y) h after plating, cells were treated with RTA 408 for 24 hours. Following treatment, cells were washed twice with cold PBS and harvested in lysis buffer. Cells were sonicated and debris was cleared by centrifugation (10 min @ 18,000 rcf, Beckman Coulter, microfuge 18 centrifuge). Total protein in supernatant was quantified using Bio-Rad protein reagent with BSA as a standard. Equal amounts of total cellular protein were separated on SDS-PAGE, and proteins were transferred to nitrocellulose membrane. Membranes were blocked for 1 hour in TBST (1×TBS with 0.1% Tween-20) containing 5% milk, washed 3 times with TBST, and incubated with primary antibodies overnight at 4° C. NQO1 antibody was from Abcam (#AB2346); HMOX1 (HO-1) antibody was from Santa Cruz (#sc-10789); actin antibody was from Millipore (#MAB 1501). After washing with TBST, secondary antibodies were added in TBST+5% milk for 1 h at room temperature. AffiniPure goat anti-rabbit or anti-mouse IgG secondary antibodies were from Jackson ImmunoResearch (catalog #111-035-144 and #115-035-146, respectively). Membranes were washed in TBST, developed using ECL, and exposed to X-ray film. Treatment with RTA 408 also increased NQO1 protein levels in SH-SY5Y cells in a dose-dependent manner (FIG. 6 a). HMOX1 protein was not detected in untreated or RTA 408-treated SH-SY5Y cells. In BV2 cells, treatment with RTA 408 increased NQO1 and HMOX1 protein levels at concentrations up to 125 nM (FIG. 6 b). The EC₅₀ value for induction of Nrf2 protein expression in SK-N-SH cells by RTA 408 (56.4 nM) was 45%-65% lower than the EC₅₀ values for 63171 (122 nM), 63189 (102 nM), and 63179 (126 nM). The same amount of 63170 (54.6 nM) was required.

The EC₅₀ was measured using an in-cell western NQO1 assay where the cells were incubated with the compound under evaluation for three days. After incubation with the compound of interest, the cells were reacted with mouse NQO1 antibody and then the next day the cells were reacted with IRDye-800CW-anti-mouse IgG antibody. The target signals were visualized and then analyzed.

Consistent with induction of Nrf2 target genes and corresponding protein products, treatment of RAW264.7 mouse macrophage cells for 24 h increased NQO1 enzymatic activity in a dose-dependent manner, with increases evident at 7.8 nM (FIG. 7). NQO1 enzymatic activity was measured by a modified Prochaska assay (Prochaska and Santamaria, Anal Biochem. 169:328-336, 1988, which is incorporated herein by reference).

Taken together, these data from multiple cell lines demonstrate that treatment with RTA 408 increases transcriptional activity controlled by antioxidant response elements, increases expression of Nrf2 target genes, and increases the activity of NQO1, an Nrf2 target gene product.

3. Effect of RTA 408 on Markers of Cellular Redox Capacity

Glutathione and NADPH are critical factors required for the maintenance of cellular redox capacity. Several genes involved in the synthesis of glutathione (e.g., GCLC and GLCM) and NADPH [e.g., hexose-6-phosphate dehydrogenase (H6PD) and malic enzyme 1 (ME1)] have been demonstrated to be regulated by Nrf2 (Wu, 2011). The effect of RTA 408 treatment on total glutathione levels was evaluated in the mouse AML-12 hepatocyte cell line using the GSH-GLO™ Glutathione Assay kit (Promega, Catalog #V6912) according to the manufacturer's instructions. Treatment of AML-12 cells for 24 h with RTA 408 increased total cellular glutathione levels in a dose-dependent manner (FIG. 8). Data shown are representative of two independent experiments. A >2-fold increase in total glutathione was observed at RTA 408 concentrations as low as 15.6 nM. The EC₅₀ value using a RAW264.7 mouse model for induction of glutathione levels by RTA 408 (9.9 nM) was 22%-57% lower than the EC₅₀ values for 63170 (12.1 nM), 63171 (23.2 nM), and 63189 (16 nM).

The effect of RTA 408 treatment on the levels of NADPH, as measured by the absorbance of a redox-sensitive dye, WST-1 (Roche Applied Science, Catalog #11644807001), was evaluated in HCT-116 cells. WST-1 absorbance is commonly used to assess cell viability by measuring glycolytic production of NAD(P)H by viable cells. Therefore, in situations where NADPH production increases in the absence of any effect on cell viability, WST-1 absorbance also increases (Berridge et al. Biochemica 4:14-19, 1996, which is incorporated herein by reference). Several key genes involved in NADPH production have also been shown to be regulated by Nrf2 (Thimmulappa et al., 2002; Wu, et al., 2011, which are both incorporated herein by reference). RTA 408 treatment for 24 h increased WST-1 absorbance in a dose-dependent manner (FIG. 9), suggesting that NADPH levels were increased.

The effect of RTA 408 on the expression of genes involved in NADPH synthesis pathways was also evaluated in this study. HCT-116 cells were treated with RTA 408 for 24 h, and mRNA levels of H6PD, phosphogluconate dehydrogenase (PGD), transketolase (TKT), and ME1 were measured using quantitative PCR. HCT-116 cells were plated in 6-well dishes at a density of 3×10⁵ cells/well. The following day, cells were treated with DMSO (vehicle), 10 nM RTA 408, or 50 nM RTA 408 for 24 h. Each well received the same amount of vehicle. Following treatment, media was removed and cells were harvested using RLT buffer (Qiagen). Lysates were homogenized using QIAShredder columns (Qiagen, Catalog #79654) and RNA was isolated using RNeasy Mini kits (Qiagen, Catalog #74104). For reverse transcription, RNA (1 μg) was combined with Oligo(dT)12-18 primer and H₂O in a final volume of 23.25 μL. The mixture was heated to 70° C. for 10 min and then placed on ice. A master mix containing 8 μL 5× 1st strand buffer, 2 μL 1 mg/ml BSA, 2 μL 20 mM DTT, 4 μL 5 mM dNTP mix, 0.25 μL RNaseOUT™ and 0.5 μL SUPERSCRIPT® II reverse transcriptase was added to the RNA mixture and incubated at 42° C. for 1 h. The reaction was inactivated by heating to 70° C. for 10 min. The reaction mixture was diluted 1:3 with H₂O prior to use in qPCR. 2.5 μL of the diluted reverse transcription reaction was combined with one set of PCR primers (0.36 μM final concentration), 2× iQ™ SYBR® Green Supermix (Bio-Rad, Catalog #170-8885) and H₂O to a final volume of 20 μL. Sequences for PCR primers are as follows: Ribosomal protein S9 (RPS9) forward primer 5′-GATGAGAAGGACCCCACGGCGTCTG-3′ (SEQ ID NO: 7), reverse primer 5′-GAGACAATCCAGCAGCCCAGGAGGG-3′ (SEQ ID NO: 8); Hexose-6-phosphate dehydrogenase (H6PD) forward primer 5′-GAGGCCGTGTACACCAAGAT-3′ (SEQ ID NO: 11), reverse primer 5′-AGCAGTGGGGTGAAAATACG-3′ (SEQ ID NO: 12), Phosphogluconate dehydrogenase (PGD) forward primer 5′-AAGGCACTCTACGCTTCCAA-3′ (SEQ ID NO: 13), reverse primer 5′-AGGAGTCCTGGCAGTTTTCA-3′ (SEQ ID NO: 14), Transketolase (TKT) forward primer 5′-CATCTCCGAGAGCAACATCA-3′ (SEQ ID NO: 15), reverse primer 5′-TTGTATTGGCGGCTAGTTCC-3′ (SEQ ID NO: 16); Malic enzyme 1 (ME1) forward primer 5′-TATATCCTGGCCAAGGCAAC-3′ (SEQ ID NO: 17) reverse primer 5′-GGATAAAGCCGACCCTCTTC-3′ (SEQ ID NO: 18). All primers had previously been validated for specificity and amplification efficiency. cDNA was amplified using the following cycle conditions: (95° C. for 3 min, 44 cycles of 95° C. for 30 sec, 60° C. for 15 sec, 72° C. for 15 sec, followed by a melt curve of 55° C. to 95° C. in increments of 0.5° C.). The relative abundance of each target gene was determined using the comparative CT method (ΔΔCT). PCR reactions were run in triplicate wells for each sample. Two independent experiments were performed using the conditions described above. Treatment with RTA 408 resulted in a dose-dependent increase in expression of genes involved in NADPH synthesis (FIGS. 10 a-d).

In summary, treatment with RTA 408 increased total glutathione levels in AML-12 hepatocytes and increased WST-1 absorbance, a marker of NADPH production, in HCT-116 cells. This observation correlated with an increase in the expression of several key genes encoding enzymes involved in NADPH synthesis.

4. Effect of RTA 408 on TNFα-Induced NF-κB Signaling

NF-κB is a transcription factor that plays a central role in the regulation of many immune and inflammatory responses. RTA 402 and other AIMs have been shown to inhibit pro-inflammatory NF-κB signaling in a variety of cell lines (Shishodia, 2006; Ahmad, 2006; Yore, 2006). Using the mouse NIH3T3/NF-κB-luc cell line (Panomics), the effects of RTA 408 and the compounds 63171, 63179, 63170, and 63189 on the NF-κB-Luc reporter were explored. The NIH3T3/NF-κB-luc cell line maintains a chromosomal integration of a Firefly luciferase reporter construct regulated by eight copies of the NF-κB response element. The effects of these compounds can be quantified by measuring the value of the NF-κB IC₅₀. RTA 408 showed a 1.2 μM IC₅₀, which when normalized for viability showed an IC₅₀ of 1.4 μM. The other four compounds showed NIH3T3/NF-κB IC₅₀ values of 1.7, 0.2, 1.1, and 1.1 μM, which when viability normalized showed IC₅₀ values of 1.8, 0.6, 1.1, and 1.0 μM, respectively. RTA 408 and its effects on NF-κB are plotted as a function of dosing and relative fold change as well as WST1 and WST1/2 are shown in FIGS. 11 a & b. The effect of RTA 408 on TNFα-induced NF-κB signaling was evaluated in HeLa/NF-κB-Luc cells, a human cervical adenocarcinoma cell line stably transfected with a luciferase reporter construct under the control of multiple NF-κB transcriptional response elements. HeLa/NF-κB-Luc cells were pretreated for 1 h with RTA 408, followed by treatment with TNF-α (10 ng/mL) for an additional 5 h. After treatment, luminescence was measured, and the effect of RTA 408 pretreatment on TNF-α-induced luciferase activity was determined. The average results and standard deviations from three independent experiments are shown in FIG. 12. RTA 408 dose-dependently inhibited TNF-α-induced NF-κB activation with an IC₅₀ value of 517±83 nM. Similar results were observed in another NF-κB reporter cell line (A549/NF-κB-Luc) where RTA 408 inhibited TNF-α-induced NF-κB activation with an IC₅₀ value of 627 nM (range 614-649 nM). RTA 408 was 1.6-1.8 fold more efficient at reducing expression from the NF-κB promoter reporter in HeLa/NF-κB-Luc cells than 63189 (854 nM) and 63170 (953 nM), respectively. Further experimentation with the human A549 cell line showed an IC₅₀ for RTA 408 as 1.7 μM and a value that has been viability normalized to 1.7 μM. The IC₅₀ of RTA 408 showed similar activity to 63189, 63179, 63171, and 63170 which showed IC₅₀ values of 1.1, 1.4, 2.0, and 1.0, respectively. When those values were viability normalized, the assay showed 1.2, 1.5, 2.1 and 1.1 μM IC₅₀, respectively. The fold change for NF-κB as a function of RTA 408 concentration along with WST1 and WST1/2 curves were plotted and are shown in FIGS. 13 a& b.

The effect of RTA 408 on TNF-α-induced phosphorylation of IκBα, a key step in activation of the NF-κB pathway, was also evaluated in HeLa cells. HeLa cells were pretreated with RTA 408 for 6 h, followed by treatment with TNF-α (20 ng/mL) for 5 min. Total and phosphorylated levels of IκBα were evaluated by Western blot. Primary IκBα antibodies were from Santa-Cruz (sc-371), pIκBα antibody was from Cell Signaling (9246), actin antibody was from Millipore (MAB 1501). Peroxidase-conjugated affini-pure Goat anti-Rabbit (IgG) and peroxidase-conjugated affini-pure Goat anti-Mouse IgG secondary antibodies were purchased from Jackson ImmunoResearch. Protein blots were developed using ECL, and exposed to X-ray film. Consistent with the results from the luciferase reporter assay, RTA 408 inhibited TNF-α-induced phosphorylation of IκBα in a dose-dependent manner (FIG. 14).

RTA 408 has also been demonstrated to inhibit other pro-inflammatory signaling pathways, such as IL-6-induced signal transducer and activator of transcription 3 (STAT3) phosphorylation and receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis. In HeLa cells, pretreatment with 1 μM RTA 408 for 6 h inhibited phosphorylation of STAT3 induced by IL-6. STAT3 (124H6) and phospho-STAT3 (Tyr705) monoclonal antibodies were from Cell Signaling Technology. Peroxidase-conjugated Affini-pure Goat anti-Rabbit IgG and Peroxidase-conjugated Affini-pure Goat anti-Mouse IgG were from Jackson ImmunoResearch. Osteoclastogenesis is a multi-step differentiation process that results from the binding of RANKL to its receptor, RANK, on cells of hematopoietic origin. This results in the activation of NF-κB and MAPK, which in turn increase transcription of osteoclast-specific target genes, including tartrate-resistant acid phosphatase (TRAP). The effect of RTA 408 on RANKL-induced osteoclastogenesis was evaluated in the mouse macrophage cell line RAW264.7. RAW 264.7 cells were plated in 24-well plates at a density of 5,000 cells/well. The next day, cells were treated with RTA 408 for 2 h and then treated with 50 ng/mL recombinant mouse RANKL (R&D systems). The treated cells were incubated for four days to allow differentiation into osteoclasts. Differentiation into osteoclasts was assessed by measuring TRAP activity. In brief, 90 μl of conditioned cell culture media was removed from each test well and aliquoted into triplicate wells (30 μL/well) of a 96-well plate. 170 μL of TRAP Assay buffer (Kamiya Biomedical) was then added to each well and the plate was incubated at 37° C. for 3 hours. Following the incubation, absorbance at 540 nm was determined using a Spectramax M2 plate reading spectrophotometer. RTA 408 dose-dependently inhibited RANKL-induced TRAP activity and the formation of osteoclasts, with an IC₅₀ of ˜5-10 nM.

5. Effect of RTA 408 on Expression of Genes Encoding Transaminase Enzymes

Transaminase elevations were observed in the 28-day toxicity studies with RTA 408 in rats and, to a much lower extent, in monkeys. Similar findings have been observed following oral administration of a related AIM (bardoxolone methyl) in humans (Pergola, 2011). One hypothesis for this effect is that AIMs directly or indirectly increase transaminase gene expression in the absence of cellular toxicity. To assess whether treatment with RTA 408 affects transaminase mRNA levels, mouse AML-12 hepatocytes were treated with RTA 408 for 18 h, and the mRNA levels of genes encoding transaminases were measured using quantitative PCR. AML-12 cells were plated in 6-well culture dishes at 3×10⁵ cells per well using 2 mL of media per well. The following day cells were treated with DMSO (vehicle) or 250 nM and 500 nM RTA 408 for 18 h at 37° C. Each well received 0.1% DMSO. Three independent replicate experiments were performed. Following treatment, media was removed and cells were harvested using RLT buffer (Qiagen). Lysates were homogenized using QIAShredder columns (Qiagen, Catalog #79654) and RNA was isolated using RNeasy Mini kits (Qiagen, Catalog #74104). For reverse transcription, RNA (1 μg) was combined with Oligo(dT)12-18 primer and H₂O in a final volume of 23.25 μL. The mixture was heated to 70° C. for 10 min and then placed on ice. A master mix containing 8 μL 5× 1st strand buffer, 2 μL 1 mg/ml BSA, 2 μL 20 mM DTT, 4 μL 5 mM dNTP mix, 0.25 μL RNaseOUT™ and 0.5 μL SUPERSCRIPT® II reverse transcriptase was added to the RNA mixture and incubated at 42° C. for 1 h. The reaction was inactivated by heating to 70° C. for 10 min. The reaction mixture was diluted 1:3 with H₂O prior to use in qPCR. 2.5 μL of the diluted reverse transcription reaction was combined with one set of PCR primers (0.36 μM final concentration), 2× iQ™ SYBR® Green Supermix (Bio-Rad, Catalog #170-8885) and H₂O to a final volume of 20 μL. Sequences for PCR primers are as follows: Ribosomal protein L19 (Rpl19) forward primer 5′-TCAGGCTACAGAAGAGGCTTGC-3′ (SEQ ID NO: 19), reverse primer 5′-ACAGTCACAGGCTTGCGGATG-3′ (SEQ ID NO: 20); NAD(P)H dehydrogenase, quinone 1 (Nqo1) forward primer 5′-TCGGGCTAGTCCCAGTTAGA-3′ (SEQ ID NO: 21), reverse primer 5′-AAAGAGCTGGAGAGCCAACC-3′ (SEQ ID NO: 22); Glutamic pyruvic transaminase 1 (Gpt1 or Alt1) forward primer 5′-CACGGAGCAGGTCTTCAACG-3′ (SEQ ID NO: 23), reverse primer 5′-AGAATGGTCATCCGGAAATG-3′ (SEQ ID NO: 24); Glutamic pyruvic transaminase 2 (Gpt2 or Alt2) forward primer 5′-CGCGGTGCAGGTCAACTACT-3′ (SEQ ID NO: 25), reverse primer 5′-CCTCATCAGCCAGGAGAAAA-3′ (SEQ ID NO: 26); Glutamate oxaloacetate transaminase 1 (Got1 or Ast1) forward primer 5′-GGCTATTCGCTATTTTGTGT-3′ (SEQ ID NO: 27), reverse primer 5′-GACCAGGTGATTCGTACAAT-3′ (SEQ ID NO: 28); Glutamate oxaloacetate transaminase 2 (Got2 or Ast2) forward primer 5′-AGAGTCCTCTTCAGTCATTG-3′ (SEQ ID NO: 29), reverse primer 5′-ATGATTAGAGCAGATGGTGG-3′ (SEQ ID NO: 30). All primers had previously been validated for specificity and amplification efficiency. cDNA was amplified using the following cycle conditions: (95° C. for 3 min, 44 cycles of 95° C. for 30 sec, 60° C. for 15 sec, 72° C. for 15 sec, followed by a melt curve of 55° C. to 95° C. in increments of 0.5° C.). The relative abundance of each target gene was determined using the comparative CT method (AACT). PCR reactions were run in triplicate wells for each sample. Treatment with RTA 408 increased mRNA levels of alanine transaminase 1 (Alt1 or Gpt1) and aspartate transaminase 1 (Ast1 or Got1) (FIGS. 15 a,c). RTA 408 had no effect on alanine transaminase 2 (Alt2 or Gpt2) mRNA levels and reduced mRNA levels of aspartate transaminase 2 (Ast2 or Got2) (FIGS. 15 b,d). These results demonstrate that RTA 408, at the concentrations tested (250 nM or 500 nM), affects transaminase gene expression in vitro.

6. Effect of RTA 408 on Levels of Glycolytic Intermediates

Studies in diabetic mice have demonstrated that bardoxolone methyl increases muscle-specific insulin-stimulated glucose uptake (Saha, 2010). In humans, a higher percentage of patients receiving bardoxolone methyl reported experiencing muscle cramps compared with patients receiving placebo (Pergola, 2011). Muscle spasms have also been reported in diabetic patients following insulin administration, suggesting a possible association with muscle glucose metabolism. The effect of RTA 408 on glycolytic metabolism was evaluated through the assessment of lactate and pyruvate levels in cultured rodent C2C12 muscle cells. To measure lactate levels, differentiated C2C12 myotubes were treated with 1 μM or 2 μM RTA 408 or insulin for 3 h at 37° C. Buffer was removed and saved for measurement of extracellular lactate levels. Cell debris was pelleted by centrifugation (10 min at 14,000 rpm) prior to measurement of lactate. To measure intracellular lactate, cells were suspended in 0.1% Triton X-100 in PBS and lysed by shearing with a 25 gauge needle. Cell lysate was centrifuged (10 min at 14,000 rpm, 4° C.) and lactate was measured in the supernatant. Intracellular and extracellular lactate was measured using the Lactate Assay Kit (BioVision, Catalog #K607-100). Similar to treatment with insulin, treatment of differentiated C2C12 myotubes with 1 μM or 2 μM RTA 408 for 3 h significantly increased intracellular and extracellular lactate levels in a dose-dependent manner.

To measure pyruvate levels, differentiated C2C12 myotubes were treated with 250 or 500 nM RTA 408 or 100 nM insulin for 18 h. Following drug treatment, media was removed and cells were washed with PBS. Cells were lysed in Pyruvate Assay Buffer (Pyruvate Assay Kit, BioVision, Catalog #K609-100). Cell lysates were centrifuged (10 min at 14,000 rpm, 4° C.) and pyruvate levels were measured in the supernatant. Treatment of C2C12 differentiated myotubes with 250 nM or 500 nM RTA 408 for 18 h also significantly (P<0.0001, noted by asterisks) increased intracellular pyruvate levels in a dose-dependent manner (FIG. 16). Together, these results demonstrate that RTA 408, at the concentrations tested, can affect muscle glycolytic intermediates in vitro; however, it is unclear how the results from this in vitro system at the RTA 408 concentrations tested relate to the potential effects on glucose metabolism at clinically-relevant dose levels in humans.

7. In Vitro Evaluation of RTA 408 Efflux by MRP-1

One of characteristic of a drug candidate is the compound's efflux ratio. The efflux ratio measures how easily the compound is transported across a membrane. The MRP-1 protein, or the multidrug resistance-assistance protein 1, is one of a family of proteins which help to facilitate the transport of organic anions and other small molecules through cellular membranes. A larger efflux ratio typically means that the drug candidate is more readily transported out of the membrane and less available to modulate intracellular processes. Similar proteins also regulate the transport of compounds across the blood-brain barrier. The efflux ratio MRP-1 for RTA 408 (1.3) was experimentally determined to be approximately ten-fold lower than 63170 (10) and 63171 (11.2) and over 40-fold lower than 63179 (56.5) and 63189 (57.1). Without being bound by theory, RTA 408 may not be a good substrate for MRP-1 and/or a candidate for p-glycoprotein mediated efflux at the blood-brain barrier. In some embodiments, RTA 408 may be used for treating disorders of the central nervous system (CNS).

C. Protective Effects of RTA 408 in Animal Models of Lung Disease

RTA 408 was tested in several animal models of pulmonary disease to evaluate its potential efficacy in the lung. For all studies, RTA 408 was orally administered daily in sesame oil at dose levels in the range of 3 to 150 mg/kg. In most cases, RTA 408 was administered starting several days prior to the induction of the lung injury response.

1. LPS-Induced Pulmonary Inflammation in Mice

RTA 408 was tested in two studies of LPS-induced pulmonary inflammation in mice. In the first study, intended to be a preliminary dose-range finder, RTA 408 (30, 100, or 150 mg/kg) was administered orally once daily for three days, followed by LPS administration 1 h after the final dose. Bronchoalveolar lavage fluid (BALF) was collected 20 h after LPS administration (21 h after the final dose of RTA 408) and evaluated for levels of pro-inflammatory markers (i.e., IL-6, IL-12p40, TNF-α, and RANTES) using LUMINEX™ technology. RTA 408 treatment resulted in a significant reduction in IL-12p40 at all doses and in TNF-α at the 100 and 150 mg/kg doses (FIG. 17). In the second study, RTA 408 (10, 30, or 100 mg/kg) was administered daily for six days, followed by LPS administration 1 h after the final dose. In this study, significant decreases in body weight were observed at the 100 mg/kg dose level starting on Day 3. Significant reductions in TNF-α were observed at the 10 mg/kg dose, and significant reductions in IL-12p40, TNF-α, and RANTES were observed at the 30 mg/kg dose (FIG. 18 a). Further evaluation of lungs from mice in this study revealed meaningful engagement of relevant Nrf2 target genes, including significant induction of NQO1 enzyme activity (by measurement of rate of reduction of 2,6-dicholorphenol-indophenol) and increases in total GSH (GSH-GLO™, Promega, Madison, Wis.) at 10 and 30 mg/kg (FIG. 18 b).

2. Bleomycin-Induced Pulmonary Fibrosis

The effect of RTA 408 was also evaluated in models of bleomycin-induced pulmonary fibrosis in mice and rats. In the first preliminary study, RTA 408 (10, 30, or 100 mg/kg) was administered to mice daily via oral gavage for 39 days, with bleomycin challenge (intranasal) on day 10. On the last day of dosing, lung tissue was collected and histology was performed to evaluate the extent of inflammation and interstitial fibrosis. In this model, no statistically significant effects were observed at the RTA 408 doses tested (FIGS. 19 a & b). Additional evaluation was performed using a rat model of pulmonary fibrosis that has been extensively characterized at the Lovelace Respiratory Research Institute. In this study, rats were challenged with bleomycin or saline by intratracheal administration on day 0. Following the challenge, animals received RTA 408 (3, 10, or 30 mg/kg) daily via oral gavage for 28 days. Administration of the 30-mg/kg dose was stopped on day 14 due to excessive dehydration and diarrhea in the animals. For the remaining animals, bronchoalveolar lavage fluid was collected on day 28 for assessment of pro-inflammatory infiltrates by flow cytometry, and lung tissue was analyzed for hydroxyproline levels by LC-MS and histopathology. Challenge with bleomycin sulfate induced a substantial release of neutrophils and an increase in soluble collagen in the BALF, as well as an increase in hydroxyproline in the lung. Treatment with 3 and 10 mg/kg RTA 408 significantly suppressed polymorphonuclear (PMN) cell infiltration into the lungs and also produced a meaningful reduction (˜10%-20%) in hydroxyproline deposition (FIGS. 20 a & b).

Importantly, histopathological evaluation revealed a significant decrease in collagen deposition, as assessed by trichrome staining, in rats treated with RTA 408. Whereas bleomycin control animals primarily exhibited moderate staining, animals treated with 10 mg/kg RTA 408 had predominantly minimal to mild staining (Table 2).

TABLE 2 Effect of RTA 408 on collagen deposition in rat lung as assessed by intensity of trichrome staining RTA 408 RTA 408 Staining Intensity^(a) Bleomycin Control (3 mg/kg) (10 mg/kg) Minimal 0 0 3 Mild 1 0 4 Moderate 7 7 1 ^(a)Values represent intensity of staining in animals with interstitial trichrome staining in areas of bleomycin-induced lung alterations.

Further evaluation of lungs from rats in this study also revealed meaningful engagement of relevant Nrf2 target genes as assayed by Quantigene Plex 2.0 Multiplex assay (Affymetrix, Santa Clara, Calif.) (FIG. 21). RTA 408 significantly and dose-dependently increased NQO1, Txnrd, Gsr, and Gst enzyme activity in the lungs of rats exposed to bleomycin, demonstrating Nrf2 activation by RTA 408 in this disease setting. NQO1 enzyme activity was assessed by measuring the rate of reduction of DCPIP. Txnrd, Gst, and Gst enzyme activities were measured using commercially available kits from Cayman Chemical (Ann Arbor, Mich.).

3. Cigarette Smoke-Induced COPD in Mice

RTA 408 was also tested in a mouse model of cigarette smoke-induced COPD. Mice received RTA 408 (3, 10, or 30 mg/kg) daily via oral gavage for two weeks and were exposed to cigarette smoke five days per week during the RTA 408 dosing period. At the end of the study, lung tissue and BALF were collected for analysis of inflammatory infiltrates and cytokines. In this experiment, multiple-dose administration of RTA 408 at doses as low as 3 mg/kg RTA 408 resulted in significant suppression of pro-inflammatory cytokines, including KC (functional mouse homolog of human IL-8) and TNF-α as measured using LUMINEX™ Technology. A summary of results from this study is presented in FIGS. 22 a-e. An AIM analog (63355) was tested in the same study for comparison. 63355 is a compound of the formula:

Further evaluation of lungs from mice in this study also revealed meaningful engagement of relevant Nrf2 target genes (FIG. 23). NQO1 enzyme activity in the lung, measured as the rate of reduction of DCPIP, was significantly decreased by cigarette smoke exposure; administration of RTA 408 rescued this loss. Txnrd enzyme activity was also induced by the 30 mg/kg dose of RTA 408. In general Gsr enzyme activity was not altered, and Gst enzyme activity was decreased with treatment—both of which were likely the consequence of a temporal response for these enzymes. Txnrd, Gst, and Gst enzyme activities were measured using commercially available kits from Cayman Chemical (Ann Arbor, Mich.).

4. Ovalbumin-Induced Asthma in Mice

The potential activity of RTA 408 was also evaluated in a pilot study in a mouse model of ovalbumin-induced asthma. Mice were sensitized with an IP injection of ovalbumin and aluminum hydroxide on Day 0 and Day 14 and challenged intranasally with ovalbumin in saline on Days 14, 25, 26, and 27. Mice received RTA 408 (3, 10, or 30 mg/kg) daily via oral gavage on Days 1-13 and 15-27. Following sensitization and challenge with ovalbumin, vehicle-treated mice had a significant increase in the total number of leukocytes compared with positive control (dexamethasone)-treated mice. An increase in the number of T cells and B cells was also observed in the vehicle-treated mice. Treatment with RTA 408 at 30 mg/kg significantly reduced the number and percentage of B cells within the airways. RTA 408 (3 and 30 mg/kg) also significantly reduced the number of macrophages, but not the mean percentage of macrophages, detected in the airways. These observations are suggestive of potential efficacy in this model.

5. Effects of RTA 408 on LPS-Induced Sepsis in Mice

Sepsis was induced on Day 0 with an IP injection of LPS (21 mg/kg), and survival was followed until Day 4. RTA 408 (10, 30, or 100 mg/kg) was administered daily via oral gavage from Day −2 to Day 2. In the vehicle control group, 60% of the animals survived until Day 4 (higher than the ˜40% survival rate expected in this model). In the RTA 408 treatment groups, 80% of the animals in the 10 mg/kg dose group and 90% of the animals in the 30 mg/kg dose group survived until Day 4 (FIGS. 24 c & d). For the 100 mg/kg dose group, 90% of the animals survived until Day 4, with only a single death occurring on Day 4. Although these RTA 408-induced effects are indicative of profound efficacy in this model, the relatively high survival rate in the vehicle control group precluded a statistically-significant difference between the control and RTA 408-treated groups. Results obtained using the compound RTA 405 are also presented (FIGS. 24 a & b). RTA 405 is a compound of the formula:

6. Effects of RTA 408 Against Radiation-Induced Oral Mucositis

Exposure to acute radiation directed to the buccal cheek pouch of hamsters produces effects similar to those observed in oral ulcerative mucositis in humans. These effects include moderate to severe mucositis characterized by severe erythema and vasodilation, erosion of the superficial mucosa, and formation of ulcers. A single study was conducted to evaluate the effects of RTA 408 in this model. On Day 0, each hamster was given an acute radiation dose of 40 Gy directed to the left buccal cheek pouch. RTA 408 (10, 30, or 100 mg/kg) was orally administered twice daily from Day −5 to Day −1, and Day 1 to Day 15. Beginning on Day 6 and continuing until Day 28 on alternate days, oral mucositis was evaluated using a standard 6-point scoring scale. Both the 30 and 100 mg/kg doses of RTA 408 caused a significant reduction in the duration of ulcerative mucositis (FIG. 25). Furthermore, a dose-dependent decrease in the percentage of animals with mucositis scores ≧3 was also observed. However, administration of RTA 408 at 30 or 100 mg/kg caused significant dose-dependent reductions in weight gain in irradiated hamsters. Due to weight loss in excess of 20%, two out of eight hamsters in the 100 mg/kg dose group were euthanized on Day 2.

7. Effect of RTA 408 on the Induction of Nrf2 Biomarkers In Vivo

As described above, a key molecular target of RTA 408 is Nrf2, a central transcriptional regulator of antioxidative cellular protection. Activation of Nrf2 induces upregulation of a battery of cytoprotective genes, including NQO1, enzymes involved in GSH synthesis [i.e., glutamate-cysteine ligase catalytic and modifier subunits (Gcic and Gclm)], enzymes involved in detoxification (i.e., glutathione S-transferases [Gsts]), and efflux transporters [i.e., multidrug resistance-associated proteins (Mrps)]. Induction of these genes results in a coordinated cellular effort to protect against oxidative insult, highlighted by increased antioxidative capacity, induction of glutathione synthesis, and conjugation and export of potentially harmful molecules from the cell. In addition to the efficacy endpoints and Nrf2 target gene expression evaluated in the various animal models described above, the ability of RTA 408 to induce expression of Nrf2 target genes was also assessed using tissues collected from healthy RTA 408-treated mice, rats, and monkeys.

As part of the non-GLP 14-day toxicity studies of RTA 408 in mice, rats, and monkeys, tissues were collected for the purposes of measuring mRNA and enzyme activity levels of selected Nrf2 target genes. For mice and rats, liver samples were collected 4 h after the final dose on Day 14. For monkeys, blood (for PBMC isolation), liver, lung, and brain tissue were collected 24 h after the final dose on Day 14. Enzyme activity for NQO1, Gst, and glutathione reductase (Gsr), as described above, were measured in tissue homogenates. Levels of mRNA were determined using Quantigene Plex 2.0 technology according to the manufacterer's protocol, which involves a hybridization-based assay using xMAP® LUMINEX® magnetic beads for direct quantification of mRNA targets. In addition, RTA 408 concentrations were measured in plasma and tissues by LC/MS/MS methods on a TQD mass spectrometer (Waters, Milford, Mass.).

RTA 408 generally increased the expression of various Nrf2 target genes in a dose-dependent manner at doses of 10, 30, and 100 mg/kg (FIG. 26, FIG. 27 a, FIGS. 28 a & b). Transcriptional upregulation of Nrf2 target genes by RTA 408 also resulted in functional increases in the antioxidant response, as manifested by dose-dependent increases in NQO1, Gst, and Gsr enzyme activity in rodent liver, as well as monkey liver and lung (FIGS. 29 a & b, FIGS. 30 a & b, FIGS. 31 a & b). Furthermore, in rodents, liver exposure of RTA 408 correlated with the level of enzyme activity of NQO1, the prototypical target gene for Nrf2 (FIG. 32 b, FIG. 33 b). In monkeys, the level of mRNA expression in PBMCs of both NQO1 and sulfiredoxin 1 (SRXN1) correlated with plasma exposure to RTA 408 (FIGS. 37 a & b). Overall, RTA 408 increased mRNA levels and activity of Nrf2 targets, and such increases generally correlated with tissue and plasma exposures, suggesting Nrf2 targets may serve as feasible biomarkers for Nrf2 activation (FIGS. 34 a & b) and may be useful for assessing pharmacological activity of RTA 408 in healthy human subjects.

D. Safety Pharmacology

A GLP-compliant safety pharmacology program was completed using RTA 408. This included in vitro and in vivo (monkey) studies on the cardiovascular system, as well as studies on the respiratory system and central nervous system in rats.

1. Evaluation of the Effects of RTA 408 on Cloned hERG Channels Expressed in HEK293 Cells

This study was conducted to assess the effects of RTA 408 on the rapidly activating inward rectifying potassium current (I_(Kr)) conducted by hERG (human ether-a-go-go-related gene) channels stably expressed in the human embryonic kidney (HEK293) cell line. The effects of RTA 408 on the hERG-related potassium current were assessed using whole-cell patch clamp electrophysiology methods. RTA 408 was determined to have IC₅₀ value of 12.4 μM in a hERG QPatch Kv11.1 assay. This value was 2.5-3 fold higher than the values for 63170 (4.9 μM) and 63189 (3.8 μM), respectively. The RTA 408 IC₅₀ value was similar to the 63171 value (15.7 μM).

2. Cardiovascular Evaluation of RTA 408 in the Cynomolgus Monkey

A single study was conducted to evaluate the potential cardiovascular effects of RTA 408 in conscious freely moving cynomolgus monkeys. The same four male and four female cynomolgus monkeys were administered the vehicle (sesame oil) and RTA 408 at dose levels of 10, 30, and 100 mg/kg according to a Latin square design, with one animal/sex/treatment dosed each week followed by a 14-day washout period between administrations, until each animal received all treatments. Vehicle and RTA 408 were administered to all animals via oral gavage at a dose volume of 5 mL/kg.

Animals were instrumented with telemetry transmitters for measurement of body temperature, blood pressure, heart rate, and electrocardiogram (ECG) evaluation. Body temperature, systolic, diastolic, and mean arterial blood pressure, heart rate, and ECG parameters (QRS duration and RR, PR, and QT intervals) were monitored continuously from at least 2 h pre-dose until at least 24 h post-dose. ECG tracings were printed at designated time points from the cardiovascular monitoring data and were qualitatively evaluated by a board-certified veterinary cardiologist. Prior to the first administration on study, untreated animals were continuously monitored for cardiovascular endpoints for at least 24 h, and these data were used in the calculation of the corrected QT interval throughout the study.

Observations for morbidity, mortality, injury, and availability of food and water were conducted at least twice daily for all animals. Clinical observations were conducted pre-dose, approximately 4 h post-dose, and following completion of the cardiovascular monitoring period. Body weights were measured and recorded on the day prior to each treatment administration.

RTA 408 at dose levels of 10, 30, and 100 mg/kg did not produce mortality, adverse clinical signs, or result in meaningful changes in body weight, body temperature, blood pressure, or qualitative or quantitative (PR, RR, QRS, QT intervals) ECG parameters (FIG. 35; Table 45). In the 100 mg/kg dose group, a small (1.6% on average) but statistically significant increase in the corrected QT interval was observed; however, individual animal data did not show consistent increases in QTc that would indicate a test article related effect. Consequently, due to the small magnitude of change and lack of a consistent response in individual animals, these slight increases in QTc were not considered to be related to RTA 408 treatment. Therefore, oral administration of RTA 408 produced no effects on cardiovascular function in cynomolgus monkeys at doses up to and including 100 mg/kg.

3. Neurobehavioral Evaluation of RTA 408 in Rats

The potential acute neurobehavioral toxicity of RTA 408 was evaluated in rats. Three treatment groups of 10 male and 10 female CD® [Crl:CD® (SD)] rats received RTA 408 at dose levels of 3, 10, or 30 mg/kg. One additional group of 10 animals/sex served as the control and received vehicle (sesame oil). Vehicle or RTA 408 was administered to all groups via oral gavage once on Day 1 at a dose volume of 10 mL/kg.

Observations for morbidity, mortality, injury, and availability of food and water were conducted twice daily for all animals. Observations for clinical signs were conducted prior to dosing on Day 1 and following each functional observational battery (FOB) evaluation. FOB evaluations were conducted pre-dose (Day −1) and at approximately 4 and 24 h post-dose. Body weights were measured and recorded pre-dose on Day 1.

RTA 408 at doses of 3, 10, and 30 mg/kg did not produce mortality, adverse clinical observations, or effects on any of the neurobehavioral measures tested. Slight decreases in body weight gain were observed approximately 24 h after dosing in the 30 mg/kg group that may potentially be test article-related. With respect to the basic neurobehavioral endpoints evaluated in this study, RTA 408 did not produce any adverse effects in rats at doses up to and including 30 mg/kg.

4. Pulmonary Evaluation of RTA 408 in Rats

The potential effect of RTA 408 on pulmonary function was evaluated in rats. Three treatment groups of eight male and eight female CD® [Crl:CD® (SD)] rats received RTA 408 at dose levels of 3, 10, or 30 mg/kg. One additional group of 8 animals/sex served as the control and received vehicle (sesame oil). Vehicle or RTA 408 was administered to all groups via oral gavage once on Day 1 at a dose volume of 10 mL/kg.

Observations for mortality, morbidity, injury, and availability of food and water were conducted twice daily for all animals. Clinical observations were conducted prior to dosing, approximately 4 h post-dose, and following completion of the 8-h pulmonary monitoring period. Body weights were measured and recorded on the day of RTA 408 administration. Pulmonary function (respiratory rate, tidal volume, and minute volume) was monitored for at least 1 h prior to dosing to establish a baseline and for at least 8 h post-dose.

RTA 408 at doses of 3, 10, and 30 mg/kg did not produce mortality, adverse clinical observations, or effects on any of the pulmonary parameters evaluated.

Therefore, with respect to the basic pulmonary endpoints evaluated in this study, RTA 408 did not produce any adverse effects in rats at doses up to and including 30 mg/kg.

E. Nonclinical Overview

1. Pharmacokinetics

RTA 408 has been investigated both in vitro and in vivo to assess its PK and metabolism properties. In vitro studies have been conducted to determine RTA 408 plasma protein binding and blood/plasma partitioning, cytochrome P450 (CYP450) inhibition and induction, and to identify metabolites formed by liver microsomes of mice, rats, monkeys, and humans. Data pertaining to the in vivo absorption and distribution following repeated administration of RTA 408 has been obtained primarily through monitoring of drug levels in plasma and select tissues from toxicology studies. Sensitive and selective liquid chromatography-mass spectrometry-based bioanalytical methods (LC/MS/MS) have been used to measure concentrations of RTA 408 in plasma, blood, and tissues with appropriate accuracy and precision. Measurements were performed on TQD and QToF mass spectrometers (Waters).

a. Absorption

The absorption and systemic pharmacokinetic behavior of RTA 408 was studied in mice, rats, and monkeys following single and repeated (daily) oral administration.

Following oral administration of a suspension formulation at doses of 10 to 100 mg/kg, maximal concentrations were observed within 1 to 2 h in mice, and within 1 to 24 h in rats and monkeys. Systemic exposure to RTA 408 tended to be highest in rats, with lower levels observed in mice and monkeys. Estimates of the apparent terminal half-life of RTA 408 observed after oral administration were generally in the 6- to 26-h range, though the apparent prolonged absorption phase in some instances precluded calculation of a definitive half-life estimate.

Systemic exposure to RTA 408 was generally similar in males and females. Exposure to RTA 408 following repeated daily oral administration tended to be slightly higher (≦2-fold) than the exposure observed after a single dose. Administration of RTA 408 over a dose range from 3 to 100 mg/kg in a suspension formulation generally resulted in dose-proportional increases in systemic exposure. However, administration of higher doses (100 to 800 mg/kg in monkeys; 500 to 2000 mg/kg in rats) did not result in similar increases in exposure, suggesting saturation of absorption at doses above 100 mg/kg. Following oral administration of an unoptimized (loose-filled) capsule formulation of RTA 408 (3 mg/kg) to monkeys, dose-normalized systemic exposure tended to be somewhat lower than that observed with a suspension formulation.

The absorption and systemic pharmacokinetic behavior of RTA 408 was studied in rats using single and repeated topical administration. The administration of RTA 408 over a range of 0.01% to 3% showed lower plasma concentrations relative to similar oral dosing. The systemic exposure to RTA 408 generally increased in a dose dependent manner. The topical administration was formulated as a suspension in sesame oil.

Using rabbits, the ocular absorption and systemic pharmacokinetic behavior of RTA 408 was evaluated. RTA 408 was administered topically to the eye once per day for five days. The ocular administration showed lower plasma concentration of RTA 408 relative to when RTA 408 is administered orally (FIG. 36). The amount of RTA 408 in the plasma even after five consecutive days showed only a small change compared to the concentration after the first dose relative to when RTA 408 was administered orally, where plasma concentrations were almost 100-fold higher (FIG. 36).

b. Distribution

Plasma protein binding of RTA 408 was evaluated in mouse, rat, rabbit, dog, minipig, monkey, and human plasma at RTA 408 concentrations of 10-2000 ng/mL using ultracentrifugation methodology. RTA 408 was extensively bound to plasma proteins. Plasma protein binding in the nonclinical species ranged from 93% (mouse) to >99% (minipig), with binding of 95% in the toxicology species (rat and monkey) and 97% in human. There was no evidence of concentration-dependent protein binding in any species tested. Results from blood-to-plasma partitioning experiments indicate that RTA 408 tended to distribute primarily in the plasma fraction of blood in a linear manner, with blood:plasma ratios <1.0 for all species and all concentrations tested.

The distribution of RTA 408 into tissues has been investigated after oral administration to mice, rats, and monkeys. In the 14-day non-GLP toxicity studies, select tissues (liver, lung, and brain) were collected at a single time point (4 h for rat and mouse; 24 h for monkey) after the final dose of the study was administered and were analyzed for RTA 408 content using LC/MS/MS. RTA 408 readily distributes into lung, liver, and brain. In lung, RTA 408 concentrations at 4 h in mice and rats were similar to or slightly higher (<2-fold) than concentrations in plasma, while at 24 h in monkeys, RTA 408 concentrations in lung were 6- to 16-fold higher than plasma concentrations. A similar pattern was observed for brain. In contrast, RTA 408 concentrations in liver were 5- to 17-fold higher than plasma for mice and rats at 4 h, and 2- to 5-fold higher than plasma at 24 h in monkeys.

The pharmacodynamic effects of RTA 408 in tissues were assessed in mice, rats, and monkeys, by monitoring the induction of Nrf2 target genes in the same tissues collected for drug exposure from the 14-day toxicity studies. Induction of Nrf2 target genes by RTA 408 resulted in increases in the antioxidant response as manifested by dose-dependent increases in NQO1, glutathione S-transferase (Gst), and glutathione reductase (Gsr) enzyme activity in the examined tissues. Enzyme activities were measured as described above. Furthermore, in rodents, RTA 408 liver content correlated with the level of enzyme activity for NQO1, the prototypical target gene for Nrf2. In monkeys, the level of mRNA expression in peripheral blood mononuclear cells (PBMCs) for both NQO1 and sulfiredoxin 1 (SRXN1) correlated with plasma exposure of RTA 408 (FIGS. 37 a & b). Overall, RTA 408 induced biomarkers of Nrf2 in rodents and monkeys, and such inductions generally correlated well with tissue and plasma exposure to RTA 408.

When RTA 408 was administered to rabbits via ocular topical administration, the highest concentrations of the compound were found in the cornea, retina, or iris while the vitreous humor, aqueous humor, and plasma showed significantly lower concentrations of RTA 408 (FIG. 38).

c. Metabolism

The metabolism of RTA 408 has been investigated after in vitro incubation of RTA 408 for 60 min with liver microsomes from mice, rats, monkeys, and humans in the presence of a nicotinamide adenine dinucleotide phosphate (NADPH)-regenerating system and a uridine diphosphate glucuronosyltransferase (UGT) reaction mixture. Extensive turnover of RTA 408 was observed with primate microsomes, with <10% of the parent molecule remaining at the end of the 60-min incubation in both monkey and human microsomes. In contrast, the extent of metabolism was lower in rodent microsomes, with >65% of the parent molecule remaining at the end of the incubation. The lack of available authentic standards for the various potential metabolites of RTA 408 precluded quantitative evaluation of the observed metabolites. From a qualitative perspective, a similar pattern of RTA 408 metabolites was observed across species, and included peaks with masses consistent with reduction and hydroxylation of RTA 408 as well as glucuronidation of RTA 408 or of its reduction/hydroxylation metabolites. No unique human metabolites were observed, with all peaks in the human microsome incubations also being observed in one or more of the preclinical species. In particular, based on in vitro microsome data, all human metabolites were present in rat or monkey, the selected rodent and non-rodent toxicity species.

d. Pharmacokinetic Drug Interactions

The potential for RTA 408 to inhibit cytochrome P450 (CYP450)-mediated metabolism was evaluated using pooled human liver microsomes and standard substrates for specific CYP450 enzymes. RTA 408 directly inhibited CYP2C8 and CYP3A4/5 with K_(i) values of approximately 0.5 μM for each enzyme. No meaningful inhibition was observed for the other enzymes tested (CYP1A2, CYP2B6, CYP2C9, CYP2C19, or CYP2D6), with inhibition <50% at the highest concentration tested (3 μM). In addition, there was little or no evidence of metabolism-dependent inhibition of any of the enzymes tested. Future studies investigating the potential for CYP3A4/5-mediated drug-drug interactions may be warranted based on these data, and the potentially high concentrations that may be achieved locally in the gastrointestinal (GI) tract after oral administration.

The potential for RTA 408 to induce CYP450 enzyme expression was evaluated using cultured human hepatocytes. Under conditions where prototypical inducers caused the expected increases in CYP activity, RTA 408 (up to 3 μM) was not an inducer of CYP1A2, CYP2B6, or CYP3A4 enzyme activity in cultured human hepatocytes. Enzyme activity was measured by monitoring substrate conversion of phenacetin, bupropion, and testosterone for CYP1A2, CYP2B6, and CYP3A4, respectively, in isolated microsomes.

F. Effects of RTA 408 on Acute Radiation Dermatitis

The effects of RTA 408 as a topical or oral preventative for acute radiation dermatitis have been examined. Using male BALB/c mice, a 30 Gy dose of radiation was administered on day 0 (Table 3). The sesame oil vehicle or RTA 408 was administered to the rats on day −5 to −1 and days 1 to 30. RTA 408 was administered both orally in 3, 10, and 30 mg/kg in sesame oil and topically in percentage composition of 0.01%, 0.1%, and 1% in sesame oil. The dermatitis was blindly evaluated every other day from day 4 to day 30. On day 12, the typical peak of dermatitis was observed and 4 mice were sacrificed 4 hours after administration of the dose. The remaining mice were sacrificed on day 30 at 4 h post-dose. Plasma was collected on days 12 and 30 as well as irradiated skin samples for mRNA and histological examination.

TABLE 3 Study Design for Acute Radiation Dermatitis Model Number of Radiation Treatment Group Animals (Day 0) Treatment Schedule 1  9 males — Untreated — 2 10 males 30 Gy Untreated — 3 14 males 30 Gy Vehicle Control Day −5 to −1 & (sesame oil) Day 1 to 30 4 14 males 30 Gy RTA 408 - 0.01% Day −5 to −1 & or 3 mg/kg Day 1 to 30 5 14 males 30 Gy RTA 408 - 0.1% or Day −5 to −1 & 10 mg/kg Day 1 to 30 6 14 males 30 Gy RTA 408 - 1% or Day −5 to −1 & 30 mg/kg Day 1 to 30

In the test groups where the mice were treated with RTA 408, the incidence of dermatitis appeared to be slightly diminished in severity when RTA 408 was given in either an oral or topical administration (FIGS. 39-42). Furthermore, curves plotting the average dermatitis clinic score for the test groups as a function of time show some change with the administration of RTA 408 either in oral or topical form from the untreated test groups (FIGS. 43-45) particularly in the case where RTA 408 was given through an oral administration. Furthermore, as can be seen in Tables 4 and 5 below, the percentage of mice suffering from dermatitis with a clinical score above 3 was significantly lower for mice treated with RTA 408 through an oral administration while the percentage of mice suffering from dermatitis with a clinical score above 2 was slightly lower for test groups who were given a topical administration of RTA 408.

TABLE 4 Percentage of mice per testing group which scored above 2 in their clinical dermatitis exam and given a topical treatment containing RTA 408 % animal- % animal- Day 12 Day 14 Day 16 Day 18 Day 20 Day 22 Day 24 Day 26 Day 28 Day 30 days >=2 days >=3 1 no radiation, untreated 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2 irradiated, untreated 0.0 50.0 83.3 83.3 83.3 100.0 66.7 50.0 50.0 50.0 35.6 0.0 3 irradiated, sesame oil 21.4 45.0 60.0 50.0 40.0 40.0 0.0 0.0 0.0 0.0 16.6 0.0 4 irradiated, RTA 0.0 0.0 20.0 50.0 10.0 40.0 40.0 40.0 20.0 10.0 14.4 0.0 408-0.01% 5 irradiated, RTA 7.1 10.0 20.0 80.0 60.0 40.0 30.0 10.0 0.0 0.0 16.3 0.0 408-0.1% 6 irradiated, RTA 10.7 20.0 10.0 70.0 30.0 10.0 0.0 0.0 0.0 0.0 9.7 0.0 408-1.0%

TABLE 5 Percentage of mice per testing group which scored above 3 in their clinical dermatitis exam and given an oral treatment containing RTA 408 % animal- % animal- Day 16 Day 18 Day 20 Day 22 Day 24 Day 26 Day 28 days >=2 days >=3 1 no radiation, untreated 0 0 0 0 0 0 0 0.0 0.0 2 irradiated, untreated 20 40 20 20 20 20 20 39.0 8.8 3 irradiated, sesame oil 35 50 40 30 20 0 0 45.6 10.9 4 irradiated, RTA 408-3 mg/kg 10 10 0 0 0 0 0 32.5 1.3 5 irradiated, RTA 408-10 mg/kg 10 25 30 0 0 0 0 33.8 4.1 6 irradiated, RTA 408-30 mg/kg 10 20 10 0 0 0 0 28.8 2.5

G. Effects of RTA 408 on Fractionated Radiation Dermatitis

Utilizing RTA 408 through topical administration, the effects of RTA 408 towards ameliorating the effects of fractionated radiation dermatitis were measured. Using Balb/c mice, RTA 408 in a topical preparation was administered to the mice daily from day −5 to day 30 in three doses ranging from 0.01% to 1%. The mice were irradiated on days 0-2 and 5-7 with six 10-Gy doses per day. Clinical dermatitis scores for the mice were evaluated blindly every two days from day 4 until the end of the study. In FIG. 46, the graph shows the change in the average clinical score for each group were plotted as a function of time. The graph shows a statistically significant improvement in the scores for mice treated with 0.1% to 1% topical formulations of RTA 408. Study and treatment parameters can be found in Table 6.

TABLE 6 Study Conditions for Fractionated Radiation-Induced Dermatitis Radiation Number of (Days Treatment Group Animals 0-2, 5-7) Treatment Schedule 1  9 males — Untreated — 2 14 males 6 × 10 Gy Untreated — 3 18 males 6 × 10 Gy Vehicle Control QD Days −5 to 30 (sesame oil) 4 18 males 6 × 10 Gy RTA 408 - 0.01% QD Days −5 to 30 5 18 males 6 × 10 Gy RTA 408 - 0.1% QD Days −5 to 30 6 18 males 6 × 10 Gy RTA 408 - 1% QD Days −5 to 30 By analyzing the average clinical scores that were shown in FIG. 46, an area under the curve (AUC) analysis was performed, which yielded the severity of the dermatitis relative to how long the dermatitis persisted. This AUC analysis allowed for direct comparison between the different groups of mice and the effect of the different percentage compositions of RTA 408 (FIG. 47 and Table 7). Administration of topical RTA 408 formulations reduced Grade 2 and Grade 3 lesions from 60% and 33% when the mice were only exposed to the vehicle to 21% and 6% with RTA 408 at 1%, concentration, respectively. The other RTA composition showed some activity but was not as significant as that shown by the 1% formulation.

TABLE 7 Percentage of Dermatitis Score for Each Treatment Group Group % Days ≧2 % Days ≧3 No Rad, No Tx 0% 0% Rad, No Tx 66% 31% Rad, Sesame Oil 60% 33% Rad, RTA 408 (0.01%) 54% 29% Rad, RTA 408 (0.1%) 40% 13% Rad, RTA 408 (1%) 21% 6%

H. Synergistic Effects of RTA 408 and Cancer Therapeutic Agents on Tumor Growth

A study of the effects of RTA 408 used in combination with traditional chemotherapeutic agents was carried out to determine the efficacy of the potential treatment. In vitro studies were carried out to determine the effects of RTA 408 on two different prostate cancer cell lines, LNCaP and DU-145. As can be seen in FIG. 48 a, the treatment of the prostate cancer cell lines (LNCaP) in vitro with 5-fluorouracil shows a statistically significant increase in cytotoxicity when combined with RTA 408 at doses from ranging from 0.125 to 0.5 μM. Using the prostate cell line DU-145 and docetaxel, RTA 408 amplified the cytotoxicity of the chemotherapeutic agent in a statistically significant fashion for dosing of RTA 408 from 0.125 to 0.75 μM as shown in FIG. 48 b. This evidence supports the concept that RTA 408 could act synergistically with cancer therapeutic agents and may be used in some embodiments to provide greater efficacy in treating cancer patients.

After the successful results of the in vitro assay, a pilot in vivo assay was carried out using LNCaP/C4-2B and DU145 human prostate cancer engineered to express firefly luciferase (hereafter referred to as C4-2B-Luc and DU145-Luc, respectively). Of note, both of these cell lines grow in an androgen-independent fashion. Cells were cultured in RPMI 1640 supplemented with 10% FBS. Cells were harvested using TrypLE Express (Invitrogen) and washed in PBS and counted. Cells were reconstituted in PBS to arrive at a final concentration of 3×10⁶ cells per 30 μL (unless otherwise stated) and aliquoted in separate tubes. Growth factor-reduced Matrigel (BD Bioscience) was thawed overnight at +4° C. and transferred into the tubes in 30 μL aliquots. The cell/Matrigel solutions were transferred to the vivarium and mixed right before injection at a 1:1 ratio. Each mouse (n=1 per group for a total of three animals) received a single subcutaneous injection of the tumor cells. Tumors were pre-established for 4 weeks. Then, one animal was treated with RTA 408 (17.5 mg/kg, i.p.) once a day for 3 days (Days −3 to −1). On the following day (Day 0), the RTA 408 treated animals and one other animal were treated with a single dose of 18 Gy IR, localized to the pelvic region where the tumors were implanted. The mouse that was pre-treated with RTA 408 received three additional doses of RTA 408 (17.5 mg/kg, i.p.), once every other day, over the following week. The third animal received no treatment and served as a positive control. Tumor progression was monitored weekly via live imaging. To detect luciferase-expressing tumor cells, mice were IP injected with D-Luciferin 5 min prior to imaging according to the manufacturer's protocol (Caliper LifeScience). Prior to imaging mice were anesthetized by isoflurane inhalation and imaged on the IVIS Lumina XR system (Caliper LifeScience). For standardization, minimal exposure time necessary to image control tumor was determined and all animals were imaged under these conditions. On Day 7, no apparent reduction in tumor size was visible in the IR treated animal compared to the control, whereas the animal receiving both RTA 408 and IR showed a smaller tumor image. On Day 14 and Day 21, the control animal showed continued tumor development and growth while the animal treated with ionizing radiation showed some improvement, most notably at Day 21. On the other hand, the animal treated with RTA 408 and ionizing radiation showed no progression from Day 7 to Day 14 and had no visible tumor on Day 21. The progress of the tumor per week can be seen in FIG. 49. Both the in vitro and in vivo data show that RTA 408 appears to complement the activity of different cancer therapeutic agents thus increasing the agent's efficacy.

I. Effects of RTA 408 on a Model of Ocular Inflammation

A study of the effects of RTA 408 on ocular inflammation was carried out using rabbits of the New Zealand albino strain. The rabbits were divided into 5 groups of 12 rabbits which were given three different concentrations of RTA 408 (0.01%, 0.1%, and 1%), Voltarene© collyre at 0.1% and the vehicle (sesame oil). Each rabbit was given three instillations within 60 min before induction of paracentesis and two instillations within 30 min after induction of paracentesis. Each instillation was 50 μL and given in both eyes. Aqueous humor for 6 animals per time-point was collected 30 min and again 2 h after induction of paracentesis. The amount of inflammation was determined by protein concentration in the aqueous humor. As shown in FIG. 50, RTA 408 showed a reduction in aqueous humor protein similar to that of the highest concentration of any of the other reference compounds (MaxiDex or mapracorat) at only 0.01% RTA 408 in the formulation. The effects of increasing concentration of RTA 408 appeared to be negligible as all concentrations of RTA 408 appeared to show relatively similar effects within error in reducing aqueous humor protein concentration.

J. Polymorph Screen

A preformulation and polymorphism study was performed for compound 63415. As part of this study, a preliminary polymorphism program was carried out with the aim to identify the most stable anhydrous form at room temperature and possible hydrates with a reasonably high probability. A total of 30 crystallization experiments, including phase equilibrations, drying experiments and other techniques, were carried out. All obtained solids were characterized by FT-Raman spectroscopy. All new forms were characterized by PXRD and TG-FTIR, and optionally by DSC and DVS.

In addition, the amorphous form was prepared and characterized. Several experiments using different techniques and approaches were carried out to prepare the amorphous form. The amorphous form was characterized by FT-Raman spectroscopy, PXRD, TG-FTIR, DSC, DVS, and Karl-Fischer titration. The stability of the amorphous form was tested at elevated humidity and temperature conditions over the course of four weeks.

1. Starting Material and Nomenclature

Two batches of 63415 were used as starting materials (Table 8). 63415 is also referred to as PP415 in this disclosure. All samples received or generated during this project received a unique identification code of the form PP415-Px, where Px refers to the sample/experiment number (x=1, 2, . . . , n).

TABLE 8 Starting materials Sample Material Amount Received PP415-P1 63415, batch #: 0141-66-1; 5.0 g Mar. 25, 2011 MW = 554.7 g/mol, C₃₃H₄₄F₂N₂O₃ PP415-P40 63415, batch #: 2083-69-DC; 5.0 g May 27, 2011 MW = 554.7 g/mol, C₃₃H₄₄F₂N₂O₃

2. Compound 63415, Batch #0414-66-1 (PP415-P1): The Amorphous Form

The 63415, batch #0414-66-1, starting material was characterized by FT-Raman spectroscopy, PXRD, TG-FTIR, Karl-Fischer titration, ¹H-NMR, DSC, DVS, and approximate solubility measurements. The results are summarized in Table 9.

TABLE 9 Characterization of the 63415 starting material (PP415-P1) Method Results FT-Raman will be used as the reference PXRD no sharp peak pattern, material is amorphous TG-FTIR ~0.9 wt.-% (~0.1 eq.) EtOH with traces of H₂O from 25° C. to 200° C., decomposition at T > 290° C. Karl- 0.5 wt.-% H₂O Fischer ¹H-NMR agrees with structure, ~0.08 eq. EtOH DSC 1^(st) heating scan: glass transition T_(g) = 152.7° C. (ΔCp = 0.72 J/g° C.); 2^(nd) heating scan: glass transition T_(g) = 149.7° C. (ΔCp = 0.45 J/g° C.) DVS slightly hygroscopic; Δm = +0.4% (50%→85% r.h.); FT-Raman and PXRD unchanged

The FT-Raman spectrum (FIG. 58) will be used as the reference spectrum for the starting material. PXRD (FIG. 59) shows no sharp peak pattern. The broad halo at ˜10-20° 2θ is characteristic for amorphous materials.

The TG-FTIR thermogram (FIG. 60) shows the gradual loss of ˜0.9 wt.-% EtOH (i.e., ˜0.1 eq.) with traces of H₂O between 25 and 200° C. Decomposition starts at T>290° C.

A water content of 0.5 wt.-% was determined by Karl-Fischer titration.

The ¹H-NMR spectrum (FIG. 61) agrees with the structure and shows ˜0.08 eq. EtOH, in agreement with the TG-FTIR thermogram.

The DSC thermogram (FIG. 62) shows in a first heating scan a glass transition of the amorphous material at T_(g)=152.7° C. (ΔC_(p)=0.72 J/g° C.). In a second scan after quench cooling, the glass transition occurs at T_(g)=149.7° C. (ΔC_(p)=0.45 J/g° C.).

The DVS isotherm (FIG. 63) shows that a gradual mass loss of 1.0 wt.-% occurred upon lowering the relative humidity from 50% r.h. to 0% r.h.; equilibrium was reached at 0% r.h. Upon increasing the relative humidity to 95% r.h. a gradual mass gain of 2.1 wt.-% (relative to the mass at 0% r.h.) occurred; equilibrium was reached at 95% r.h. Upon lowering the relative humidity from 95% r.h. to 50% r.h. the final mass was 0.2 wt.-% below the starting mass. The mass increase of 0.4 wt.-% at 85% r.h. (relative to the starting mass) classifies the sample as slightly hygroscopic.

The FT-Raman spectrum (FIG. 64) and PXRD pattern (FIG. 65) of the sample after the DVS measurement are unchanged compared to the spectrum and pattern of the sample before the measurement.

The approximate solubility of the PP415-P1 starting material was measured in twelve solvents and four solvent mixtures at r.t. by manual dilution combined with visual observation (Table 10). Due to the experimental error inherent in this method, the solubility values are intended to be regarded as rough estimates and are to be used solely for the design of crystallization experiments. All solvent mixtures are listed as ratios by volume (v/v).

TABLE 10 Approximate solubility of the PP415-P1 (amorphous) starting material Solvent Solubility S [mg/mL] toluene S > 200 DCM S > 200 EtOAc S > 210 acetone S > 230 MeCN S > 230 DMF S > 210 MeOH S < 210 EtOH^(a) 105 < S < 210 2PrOH 16 < S < 19 DEE S ≧ 1^(d )  heptane S < 1  H₂O S < 1  2PrOH/H₂O (9:1)^(b) 7.9 < S < 8.5 MeCN/H₂O (2:3)^(c) S < 1  EtOAc/heptane (1:1)^(a) 100 < S < 200 toluene/DEE (1:1)^(a) S > 220 ^(a)observed precipitation after ~1 d; ^(b)water activity a(H₂O) ~0.7 at 25° C.; ^(c)water activity a(H₂O) > 0.9 at 50° C.; ^(d)incomplete dissolution at first (S < 1), but solid residue dissolved completely overnight (S > 1).

3. Compound 63415, Batch #2083-69-DC (PP415-P40): Class 2

63415, batch #2083-69-DC, is a heptane solvate. This material (PP415-P40) was characterized by PXRD and found to correspond to class 2 (FIG. 66).

Class 2 likely corresponds to isostructural, non-stoichiometric (<0.5 eq.) solvates (of heptane, cyclohexane, isopropyl ether, 1-butanol, triethyl amine, and possibly other solvents, such as hexane and other ethers) with tightly bound solvent.

The small peaks visible in the pattern of PP415-P40 at 7.9° 2θ and 13.8° 2θ do not correspond to peaks of classes 3, 4, or 5. Their origin is not clear at this point.

4. Chemical Stability of the Amorphous Form

The chemical stability of the amorphous form was investigated in different solvents over the course of seven days.

Solutions/suspensions with a concentration of 1 mg/mL were prepared in four organic solvents (acetone, MeOH, MeCN, EtOAc) and three aqueous surfactant media (1% aq. SDS, 1% aq. Tween 80, 1% aq. CTAB).

Four separate solutions/suspensions were prepared for each solvent, equilibrated for 6 h, 24 h, 2 d, and 7 d and subsequently analyzed by HPLC.

The relative area-% obtained from the HPLC chromatograms are given in Table 11. The compound seems to be somewhat unstable in the diluent (0.1% formic acid in MeCN); over the course of the sequence (i.e., within ˜24 hours) the area-% of a reference sample (PP415-P1, ran at the beginning and the end of the sequence) decreased from 99.9% to 99.3% at 254 nm and from 99.9% to 99.5% at 242 nm. Due to this effect, the samples measured towards the end of the sequence (set up in the following order: 7 d, 2 d, 24 h, 6 h), might be affected and the obtained area-% might be underestimated.

TABLE 11 Chemical stability experiments with the amorphous form of 63415 (PP415-P1)^(a) at 254 nm at 242 nm Solvent 7 d 2 d 24 h 6 h 7 d 2 d 24 h 6 h acetone 99.6% 99.6% 99.6% 99.6% 99.7% 99.7% 99.6% 99.6% EtOAc 99.8% 99.8% 99.8% 99.7% 99.8% 99.9% 99.8% 99.7% MeOH 99.8% 99.8% 99.7% 99.8% 99.8% 99.9% 99.7% 99.8% MeCN 97.7% 99.5% 99.3% 99.4% 97.4% 99.5% 99.3% 99.3% Tween 1%^(b) 97.7% 97.1% 95.1% 97.6% 98.7% 98.7% 96.2% 99.1% SDS 1%^(c) 99.7% 99.6% 99.7% 99.7% 99.8% 99.7% 99.7% 99.7% CTAB 1% 99.3% 99.4% 99.4% 99.6% 99.3% 99.4% 99.4% 99.7% ^(a)at the third wavelength (210 nm), the signal intensity was weak and the signal-to-noise ratio large, thus integration was not carried out ^(b)suspensions, not all material dissolved for all time points ^(c)suspensions, not all solid dissolved for time points 24 h and 6 h

Decomposition ≧1% was observed for solutions in MeCN after seven days and for suspensions in the 1% aqueous Tween 80 media (at all time points at 254 nm and after 24 h, 2 d, and 7 d at 242 nm).

5. Storage Stability of the Amorphous Form

To learn more about its fundamental properties and physical stability, the amorphous form of 63415 was stressed by storage at elevated temperatures and relative humidities.

Samples of the amorphous form (the PP415-P1 starting material) were stored open at 25° C./˜62% r.h. (over saturated aqueous solution of NH₄NO₃) and 40° C./˜75% r.h. (over saturated aqueous solution of NaCl) and closed at 60° C. and 80° C. (Table 12). At time points 0 w, 1 w, 2 w, and 4 w the samples were examined by PXRD and compared to the starting material, PP415-P1.

TABLE 12 Storage stability experiments with the amorphous form of 63415 (PP415-P1) Sample Conditions Time Point PXRD Result PP415-P2a open, 25° C./~62% r.h. 1 w amorphous PP415-P2b open, 25° C./~62% r.h. 2 w amorphous PP415-P2c open, 25° C./~62% r.h. 4 w amorphous PP415-P3a open, 40° C./~75% r.h. 1 w amorphous PP415-P3b open, 40° C./~75% r.h. 2 w amorphous PP415-P3c open, 40° C./~75% r.h. 4 w amorphous PP415-P4a closed, 60° C. 1 w amorphous PP415-P4b closed, 60° C. 2 w amorphous PP415-P4c closed, 60° C. 4 w amorphous PP415-P5a closed, 80° C. 1 w amorphous PP415-P5b closed, 80° C. 2 w amorphous PP415-P5c closed, 80° C. 4 w amorphous

After one week (time point 1 w, FIG. 67), two weeks (time point 2 w, FIG. 68), and four weeks (time point 4 w, FIG. 69) all four samples were still amorphous, as the powder X-ray diffractograms show no differences compared to the starting material at time point 0 w.

6. Crystallization and Drying Experiments

a. Crystallization Experiments

Phase equilibrations, crystallizations from hot solutions, and evaporation experiments were carried out starting from the amorphous form in order to identify with reasonably high probability the most stable anhydrous form at r.t. and possible hydrates. All obtained materials were characterized by FT-Raman spectroscopy; selected samples were also characterized by PXRD.

The FT-Raman spectra were grouped into classes according to the similarity of their peak positions. The original sample (PP415-P1, see Table 8) was classified along with the crystallization products. The spectra within a class, however, are not strictly identical, but similar. Small differences and peak shifts might exist. Considering the FT-Raman spectra alone, it is difficult to determine if the spectra of one class belong to the same polymorphic form.

The peaks in the PXRD patterns were determined and the patterns then classified into clusters using the PANalytical X'Pert (Highscore Plus) software. These clusters identify patterns of a high similarity. However, small but significant differences exist within a cluster. Thus, the patterns within a cluster do not necessarily correspond to the same polymorphs, but represent different forms with very similar molecular structures. The FT-Raman classes correspond in all cases to the PXRD clusters.

b. Suspension Equilibration Experiments

Suspension equilibration experiments were carried out in one solvent and eleven solvent mixtures (Table 13). Suspensions of ˜100 mg of PP415-P1 in 0.2-2.0 mL of the selected solvents were prepared and shaken for 4-15 days at 22-24° C. The solids were recovered and characterized by FT-Raman spectroscopy; most were characterized also by PXRD.

TABLE 13 Suspension equilibration experiments starting from the amorphous form (PP415-P1) FT-Raman PXRD Sample Solvent/Mixture class cluster PP415-P6 2PrOH 3 3 PP415-P7 1:2 EtOAc/heptane 2 2 PP415-P8 1:2 acetone/hexane 2 2 PP415-P9 1:3 toluene/DEE  2^(d) — PP415-P10 1:3 MeOH/TBME 2 2 PP415-P11 1:2 MEK/cyclohexane  2^(d) — PP415-P12 9:1 EtOH/H₂O^(a) 3 3 PP415-P13 7:3 MeCN/H₂O^(b)  4^(d) 4 PP415-P14 ~1:1 THF/H₂O^(c)  5^(d) 5 PP415-P29 1:2 EtOAc/TEA 2 2 PP415-P31 9:1 PEG/H₂O 1 1 PP415-P35 7:3 MeCN/H₂O^(b)  4^(d) 4 water activities: ^(a)a(H₂O) ~0.5 at 50° C.; ^(b)a(H₂O) ~0.85 at 50° C.; ^(c)a(H₂O) > 0.99 at 64° C.; ^(d)the spectrum contains solvent signals

c. Crystallizations from Hot Solutions

Hot solutions of PP415-P1 were prepared in one solvent and four solvent mixtures (Table 14). Upon slow cooling to 5° C. at a rate of ˜0.2 K/min, precipitation was observed in three cases (-P20, -P21, -P24). In two cases (-P22, -P23) no solid precipitated, even after storage at 4-5° C. for two days. Here, the solvent was evaporated under N₂ flow at r.t. The solids were recovered and characterized by FT-Raman spectroscopy and for those with spectra different from the amorphous starting material, FT-Raman class 1, also by PXRD.

TABLE 14 Slow cooling experiments starting from the amorphous form (PP415-P1) FT-Raman PXRD Sample Solvent/Mixture Conditions class cluster PP415-P20 ~2:1 acetone/H₂O 55° C. → 5° C. 3^(b) 3 PP415-P21 ~1:5 EtOH/ 75° C. → 5° C. 2  2 cyclohexane PP415-P22 ~1:3 MeCN/ 75° C. → 5° C.^(a) 1^(b) — toluene PP415-P23  1:3 EtOAc/ 75° C. → 5° C.^(a) 1^(b) — dioxane PP415-P24 1BuOH 75° C. → 5° C. 2^(b) 2 ^(a)no precipitation after slow cooling and stirring at 5° C. for 2 days; evaporated solvent under N₂ flow at r.t. ^(b)the spectrum contains solvent signals

d. Evaporation/Precipitation Experiments

Clear solutions of PP415-P1 were prepared in three solvent mixtures (Table 15). The solvents were then slowly evaporated at r.t. under ambient conditions. However, in two of the three experiments (-P15 and -P17) white solid precipitated before evaporation began. The obtained solids were examined by FT-Raman spectroscopy and PXRD.

TABLE 15 Slow evaporation experiments with the amorphous form (PP415-P1) Sample Solvent/Mixture FT-Raman class PXRD cluster PP415-P15 1:2 DCM/IPE 2^(a) 2 PP415-P16 1:2 MeOH/toluene 1^(a) — PP415-P17 1:3 EtOAc/heptane 2^(a) 2 ^(a)the spectrum contains solvent signals

e. Drying Experiments

At least one sample of each class was dried under vacuum with the aim to desolvate the solvates and to obtain non-solvated crystalline forms of 63415 (Table 16). The dried materials were characterized further by FT-Raman, PXRD, and TG-FTIR.

TABLE 16 Drying experiments carried out on samples obtained from the crystallization experiments Starting Material Sample (Class) Conditions Result PP415-P18 PP415-P15 (2) r.t., 2-10 mbar, ~2 h 2  PP415-P19 PP415-P17 (2) r.t., 2-10 mbar, ~2 h 2  PP415-P25 PP415-P6 (3) r.t., ~3 mbar, ~5 d; 3  60° C., 5-10 mbar, 2 × 1 h; 40-50° C., 5-20 mbar, ~1 d PP415-P26 PP415-P13 (4) r.t., ~3 mbar, ~5 d; 4  60° C., 5-10 mbar, 2 × 1 h; 40-50° C., 5-20 mbar, ~1 d PP415-P27 PP415-P14 (5) r.t., ~3 mbar, ~5 d; 1^(a) 60° C., 5-10 mbar, 2 × 1 h; 40-50° C., 5-20 mbar, ~1 d PP415-P28 PP415-P21 (2) r.t., ~3 mbar, ~5 d; 2^(b) 60° C., 5-10 mbar, 2 × 1 h; 40-50° C., 5-20 mbar, ~1 d PP415-P30 PP415-P7 (2) 50-70° C., 1-10 mbar, 3 d 2  PP415-P32 PP415-P19 (2) 80° C., <1 × 10⁻³ mbar, 3 d 2^(b) PP415-P33 PP415-P25 (3) 80° C., <1 × 10⁻³ mbar, 3 d 3  PP415-P34 PP415-P28 (2) 80° C., <1 × 10⁻³ mbar, 3 d 2^(b) PP415-P36 PP415-P35 (4) 80° C., <1 × 10⁻³ mbar, 3 d 4^(c) PP415-P37 PP415-P35 (4) 80° C., N₂ flow, 3 d 4^(c) PP415-P44a PP415-P41 (5) 80° C., 100 mbar, 2 d 1^(a) PP415-P46a PP415-P45 (6) 80° C., 100 mbar, 4 d 1^(a) ^(a)desolvation successful, significant reduction of solvent content, sample mainly amorphous; only few, broad peaks in PXRD ^(b)sample less crystalline, as indicated by broader peaks in PXRD ^(c)desolvation successful, significant reduction of solvent content, sample still crystalline; no change in structure

7. Characterization of New Forms (Classes)

a. Summary of New Classes

In addition to the amorphous form of 63415, four new crystalline forms were obtained in this study (Table 17).

TABLE 17 Summary of obtained classes Result of Class Characteristics Drying Experiments Class 1 amorphous form — Class 2 isostructural solvates (e.g., heptane) drying unsuccessful Class 3 isostructural solvates (e.g., ethanol) drying unsuccessful Class 4 MeCN solvate & desolvated solvate drying successful, structure unchanged Class 5 THF solvate drying resulted in amorphous form

Class 2:

Most crystallization experiments resulted in solid material of class 2. These samples likely correspond to isostructural, non-stoichiometric (<0.5 eq.) solvates (of heptane, cyclohexane, isopropyl ether, 1-butanol, triethylamine, and possibly hexane and other ethers, etc.) with tightly bound solvent molecules. The Raman spectra and PXRD patterns within this class are very similar to each other, thus the structures might be essentially identical with only small differences due to the different solvents that were incorporated.

Drying experiments on class 2 samples have not resulted in a crystalline, non-solvated form. Even elevated temperatures (80° C.) and a high vacuum (<1×10⁻³ mbar) could not remove the tightly bound solvent molecules completely; a solvent content of >2 wt.-% always remained. The crystallinity of these samples is reduced, but neither transformation into a different structure nor substantial amorphization was observed.

Class 3:

Solid material of class 3 was obtained from several crystallization experiments. The samples of class 3 are likely isostructural solvates of 2PrOH, EtOH, and probably acetone with tightly bound solvent molecules. They could correspond to either stoichiometric hemisolvates or non-stoichiometric solvates with a solvent content of ˜0.5 eq. As with class 2, the Raman spectra and PXRD patterns within this class are very similar to each other, indicating similar structures that incorporate different solvents.

Similar to class 2, drying experiments were also unsuccessful. The very tightly bound solvent molecules could only partially be removed (˜5.4 wt.-% to ˜4.8 wt.-%, up to 3 d at 1×10⁻³ mbar and 80° C.). The PXRD pattern remained unchanged.

Class 4:

Material of class 4 was only obtained from a 7:3 MeCN/H₂O solvent system. It most likely corresponds to a crystalline acetonitrile hemisolvate.

By drying (under vacuum or N₂ flow at elevated temperatures) most of the solvent could be removed without changing or destroying the crystal structure (PXRD remained unchanged). Thus, a crystalline, non-solvated form (or rather desolvated solvate) was obtained. It is slightly hygroscopic (mass gain of ˜0.7 wt.-% from 50% r.h. to 85% r.h.) and has a possible melting point at 196.1° C. (ΔH=29.31 J/g).

Class 5:

Class 5 was also obtained from only one solvent system (˜1:1 THF/H₂O) and contains bound THF (and maybe H₂O). As the content of the two components cannot be quantified separately, the exact nature of this crystalline solvate cannot be determined.

Drying of class 5 resulted in complete desolvation and transformation into the amorphous form (class 1). One possible process to prepare the amorphous form from class 2 material is a transformation of class 2 to class 5, followed by drying and amorphization.

b. Class 1—The Amorphous Form

Class 1, the amorphous form of 63415, was obtained from a few crystallization experiments (Table 18). Most crystallization experiments resulted in crystalline material of classes 2, 3, 4, or 5.

The starting material, PP415-P1, is amorphous and belongs to class 1. Further experiments, exclusively aimed at preparing the amorphous form (class 1), were carried out.

TABLE 18 Crystallization experiments resulting in solid material of class 1 Character- Sample Method Solvent ization Drying PP415-P31 susp. equil. 9:1 PEG/H₂O Raman, — PXRD PP415-P22 slow ~1:3 MeCN/toluene vis. obs., — cooling^(a) Raman PP415-P23 slow cooling 1:3 EtOAc/dioxane vis. obs., — Raman PP415-P16 evap./precip. 1:2 MeOH/toluene vis. obs., — Raman ^(a)no precipitation after slow cooling and stirring at 5° C. for 2 days; evaporated solvent under N₂ flow at r.t.

c. Class 2—Isostructural Solvates (e.g., Heptane)

Most crystallization experiments resulted in solid material of class 2 (Table 19). In addition, one batch of a class 2 heptane solvate, PP415-P40, was used as starting material (see Table 8).

The FT-Raman spectra of class 2 are clearly similar to each other (FIG. 70) but show small differences. They differ significantly from the spectrum of the amorphous starting material, class 1 (FIG. 71) and from the spectra of classes 3, 4, and 5 (FIG. 72).

The PXRD patterns of class 2 (FIG. 73) confirm the crystallinity of the materials. The patterns of the samples are very similar to each other but show small differences (FIG. 74). The class 2 patterns differ clearly from the patterns of classes 3, 4, and 5 (FIG. 75).

The TG-FTIR thermogram of sample PP415-P7 (FIG. 76) shows the loss of ˜7.5 wt.-% EtOAc and heptane in two steps from ˜100° C. to 290° C. and decomposition at temperatures T>290° C. Before the TG-FTIR experiments, the samples were dried briefly (for ˜5 min) under vacuum (10-20 mbar) to remove excess, unbound solvent. The loss of both EtOAc and heptane occur together in the same temperature range; both solvents seem tightly bound within the structure. The theoretical EtOAc content (b.p.=76° C.) of a hemisolvate is 7.4 wt.-%, the theoretical heptane content (b.p.=98° C.) of a hemisolvate is 8.3 wt.-%. Unfortunately, the content of the two components cannot be quantified separately.

The TG-FTIR thermogram of sample PP415-P21 (FIG. 77) shows the loss of ˜5.8 wt.-% cyclohexane in two steps from ˜140° C. to ˜250° C. and decomposition at temperatures T>250° C. With the boiling point of cyclohexane at 81° C., the solvent seems tightly bound within the structure. The theoretical cyclohexane content of a hemisolvate is 7.1 wt.-%. Thus, sample PP415-P18 possibly corresponds to a non-stoichiometric cyclohexane solvate (with <0.5 eq. solvent content).

The TG-FTIR thermogram of sample PP415-P24 (FIG. 78) shows the loss of ˜16.6 wt.-% 1BuOH in a step from ˜50° C. to ˜160° C., further loss of 1BuOH (6.6 wt.-%) in a second step from 160° C. to 230° C. and decomposition at temperatures T>230° C. With the boiling point of 1BuOH at 117° C., the solvent of at least the second step seems tightly bound within the structure. The theoretical 1BuOH content of a hemisolvate is 6.3 wt.-%.

The TG-FTIR thermogram of sample PP415-P29 (FIG. 79) shows the loss of ˜5.1 wt.-% EtOAc and TEA from ˜50° C. to ˜220° C., most of it in a step from 180° C. to 210° C. Decomposition occurs at temperatures T>220° C. The loss of both EtOAc and TEA occur together in the same temperature range; both solvents seem tightly bound within the structure (with the boiling point of EtOAc at 77° C. and of TEA at 89° C.).

The TG-FTIR thermogram of sample PP415-P47 (FIG. 80) shows the typical two-step mass loss for class 2 (total of ˜7.9 wt.-% EtOAc) at temperatures up to 240° C., indicating very tightly bound solvent molecules.

The TG-FTIR thermogram of sample PP415-P48 (FIG. 81) shows the mass loss of ˜3.5 wt.-% ethyl formate and water, at first gradually and then in a clear step between 180° C. and 200° C. There might be further loss of ethyl formate concomitant with the decomposition at T>240° C.

Thus, the samples of class 2 might all correspond to non-stoichiometric (<0.5 eq.), isostructural solvates with tightly bound solvent molecules. As the Raman spectra and PXRD patterns within this class are very similar to each other, the structures might be essentially identical to each other with only small distortions of the unit cell dimensions or small changes of atomic positions within the unit cell, due to the different sizes and shapes of the incorporated solvent molecules.

TABLE 19 Crystallization experiments resulting in solid material of class 2 Sample Method Solvent Characterization Drying PP415-P7 susp. equil. 1:2 EtOAc/heptane Raman, PXRD, TG-FTIR x PP415-P8 susp. equil. 1:2 acetone/hexane Raman, PXRD — PP415-P9 susp. equil. 1:3 toluene/DEE Raman, PXRD — PP415-P10 susp. equil. 1:3 MeOH/TBME Raman, PXRD — PP415-P11 susp. equil. 1:2 MEK/cyclohexane Raman — PP415-P29 susp. equil. EtOAc/TEA Raman, PXRD, TG-FTIR — PP415-P15 evap./precip. 1:2 DCM/IPE Raman, PXRD x PP415-P17 evap./precip. 1:3 EtOAc/heptane Raman, PXRD x PP415-P21 slow cooling ~1:5 EtOH/cyclohexane Raman, PXRD, TG-FTIR x PP415-P24 evap./precip. 1BuOH Raman, PXRD, TG-FTIR — PP415-P43^(a) evaporation (8:2) THF/hexane PXRD — PP415-P47^(a) evaporation EtOAc PXRD, TG-FTIR — PP415-P48^(a) evaporation ethyl formate PXRD, TG-FTIR — ^(a)starting material: PP415-P40, class 2; in all other experiments PP415-P1, class 1, was used as starting material.

d. Drying Experiments on Samples of Class 2

Several samples of class 2 were dried under vacuum (and some at elevated temperatures) and in an attempt to desolvate them with the aim to obtain an anhydrous form of 63415. Details and characterizations of the dried samples are provided below in Table 20.

However, even drying for three days at 80° C. and a vacuum <1×10⁻³ mbar could not remove the tightly bound solvent molecules completely; a solvent content of >2 wt.-% remained (see samples -P32 and -P34). The PXRD patterns show a reduced crystallinity of these samples, but no transformation into a different structure was observed.

TABLE 20 Drying experiments on class 2 samples Starting Material Dried Material Solvent Drying Solvent Sample Content Conditions Sample Content Class PP415-P7 EtOAc/heptane 50-70° C., PP415-P30 heptane 2  (~7.5%) 1-10 mbar, 3 d (~2.5%) PP415-P15 IPE r.t., 2-10 mbar, PP415-P18 IPE 2  (unknown) ~2 h (~7.0%) PP415-P17 EtOAc(?)/heptane r.t., 2-10 mbar, ~2 h PP415-P19 heptane 2  (unknown) (~7.6%) PP415-P19 heptane 80° C., <1 × 10⁻³ mbar, PP415-P32 heptane 2^(a) (~7.6%) 3 d (~2.2%) PP415-P21 cyclohexane r.t., ~3 mbar, ~5 d; PP415-P28 cyclohexane 2^(a) (~5.8%) 60° C., 5-10 mbar, (~3.0%) 2 × 1 h; 40-50° C., 5-20 mbar, ~1 d PP415-P28^(a) cyclohexane 80° C., <1 × 10⁻³ mbar, PP415-P34 cyclohexane 2^(a) (~3.0%) 3 d (~2.3%) ^(a)according to PXRD somewhat less crystalline

Thus, the class 2 solvates seem to have very tightly bound solvent molecules. They are difficult to desolvate or transform/amorphize.

e. PP415-P7→PP415-P30

The solid material of sample PP415-P7, class 2, obtained from a suspension equilibration experiment in 1:2 EtOAc/heptane was dried (as PP415-P30) under vacuum for several days (1-10 mbar, 50-70° C.).

The FT-Raman spectrum of the dried class 2 material (PP415-P30) shows small differences from the original spectrum (sample PP415-P7, FIG. 82) but still corresponds to class 2.

The PXRD pattern of the dried class 2 material (PP415-P30) shows slightly broader, less intense peaks (FIG. 83) but still corresponds to class 2.

The TG-FTIR thermogram of the dried sample PP415-P30 (FIG. 84) shows the loss of ˜2.5 wt.-% heptane (and some EtOAc) in two steps from ˜50° C. to ˜250° C. and decomposition at temperatures T>250° C. Compared to the TG-FTIR of sample PP415-P7 (FIG. 76), the two steps of solvent loss are preserved, but the total amount of solvent in the sample has decreased from ˜7.5 wt.-% in PP415-P7 to ˜2.5 wt.-% in PP415-P30.

Thus, the attempt to desolvate this solvate at elevated temperatures (50-70° C.) and a vacuum of 1-10 mbar) has caused only a partial loss of solvent.

f. PP415-P15→PP415-P18

The solid material of sample PP415-P15, class 2, obtained from a precipitation experiment in 1:2 DCM/IPE was dried (as PP415-P18) under vacuum (˜2-20 mbar) at r.t. for ˜2 h.

The FT-Raman spectrum of PP415-P18 is identical to the spectrum of sample PP415-P15 (FIG. 85), both correspond to class 2.

The PXRD pattern of PP415-P18 shows small differences to the pattern of PP415-P15 (FIG. 86). PP415-P18 still corresponds to class 2.

The TG-FTIR thermogram (FIG. 87) shows the loss of ˜7.0 wt.-% IPE in two steps from ˜140° C. to ˜250° C. and decomposition at temperatures T>250° C. With the boiling point of IPE being 67° C., the solvent seems tightly bound within the structure. The theoretical IPE content of a hemisolvate is 8.4 wt.-%.

Unfortunately, no TG-FTIR was recorded of the material before the drying step. However, as the solvent seems so tightly bound into the structure and no (or only small) changes are observed in the FT-Raman spectra and PXRD patterns, it is assumed that the drying has had no significant effect on structure or solvent content.

g. PP415-P17→PP415-P19→PP415-P32

The solid material of sample PP415-P17, class 2, obtained from a precipitation experiment in 1:3 EtOAc/heptane was dried (as PP415-P19) under vacuum (˜2-20 mbar) at r.t. for ˜2 h.

The FT-Raman spectrum of PP415-P19 is identical to the spectrum of sample PP415-P17 (FIG. 88); no changes can be observed, and both correspond to class 2.

The PXRD pattern of PP415-P19 differs slightly from the pattern of PP415-P17 (FIG. 89) but still corresponds to class 2.

The TG-FTIR thermogram (FIG. 90) shows the loss of ˜7.6 wt.-% heptane in two steps from ˜140° C. to ˜270° C. and decomposition at temperatures T>270° C. With the boiling point of heptane being 98° C., the solvent seems tightly bound in the structure. The theoretical heptane content of a hemisolvate is 8.3 wt.-%.

A further drying experiment (80° C., <1×10⁻³ mbar, 3 days) was carried out on the same sample as PP415-P32.

The FT-Raman spectrum remained unchanged (FIG. 88). The PXRD pattern still corresponded to class 2 (FIG. 89), but the sample was less crystalline (as the peaks were broader and had a lower S/N ratio).

The TG-FTIR thermogram (FIG. 90) shows the loss of ˜2.2 wt.-% heptane, most of it in a step from 170° C. to 200° C. and decomposition at temperatures T>250° C. Thus, the heptane content was reduced only from 7.6 wt.-% to 2.2 wt.-%, confirming the tight binding of the solvent molecules.

h. PP415-P21→PP415-P28→PP415-P34

The solid material of sample PP415-P21, class 2, obtained from a slow cooling experiment in ˜1:5 EtOH/cyclohexane was dried (as PP415-P28) under vacuum for several days (2-20 mbar, r.t. to 60° C.).

The FT-Raman spectrum of the dried class 2 material (PP415-P28) shows small differences to the spectrum of class 2 (sample PP415-P21, FIG. 92), but still corresponds to class 2.

The PXRD pattern of the dried class 2 material (PP415-P28) shows broader, less intense peaks compared to the pattern of PP415-P21 (FIG. 93), indicating that the dried sample is less crystalline. However, the pattern still corresponds to class 2.

The TG-FTIR thermogram of the dried sample PP415-P28 (FIG. 94) shows the loss of ˜3.0 wt.-% cyclohexane in two steps from ˜140° C. to ˜250° C. and decomposition at temperatures T>250° C. Compared to the TG-FTIR of sample PP415-P21 (FIG. 77), the two steps of solvent loss are preserved, but the total amount of solvent in the sample has decreased from ˜5.8 wt.-% in PP415-P21 to ˜3.0 wt.-% in PP415-P28.

Thus, the desolvation of this solvate seems to have caused only a partial loss of solvent, parallel to a partial loss of crystallinity.

Further drying of this sample (at 80° C., <1×10⁻³ mbar, 3 days) was carried out as PP415-P34.

The FT-Raman spectrum remained unchanged (FIG. 92). The PXRD pattern still corresponded to class 2 (FIG. 93), but the sample was less crystalline (as the peaks were broader and had a lower S/N ratio).

The TG-FTIR thermogram (FIG. 95) shows the loss of ˜2.3 wt.-% cyclohexane, in two steps from 25° C. to 270° C. and decomposition at temperatures T>270° C.

Thus, the cyclohexane content was reduced only from 3.0 wt.-% to 2.3 wt.-% confirming the tight binding of the solvent molecules.

i. Class 3—Isostructural Solvates (e.g., Ethanol)

Several crystallization experiments resulted in solid material of class 3 and were characterized by FT-Raman spectroscopy, PXRD, and TG-FTIR (Table 21).

The FT-Raman spectra of class 3 are clearly similar to each other (FIG. 96) but show small differences (FIG. 97). The spectra of class 3 differ significantly from the spectrum of the amorphous starting material, class 1 (FIG. 98), and from the spectra of classes 2, 4, and 5 (FIG. 72).

The PXRD patterns of class 3 (FIG. 99) confirm the crystallinity of the materials. The patterns of the three samples are similar to each other but show small but significant differences (FIG. 100). The class 3 pattern clearly differs from the crystalline patterns of classes 2, 4, and 5 (FIG. 75).

The TG-FTIR thermogram of sample PP415-P6 (FIG. 100) shows the loss of ˜5.4 wt.-% 2PrOH from 25° C. to 250° C., most of it in a step from ˜170° C. to 190° C. Decomposition starts at temperatures T>250° C. Before the TG-FTIR experiments, the samples were dried briefly (for ˜5 min) under vacuum (10-20 mbar) to remove excess, unbound solvent. The theoretical 2PrOH (b.p.=82° C.) content of a hemisolvate is 5.1 wt.-%.

The TG-FTIR thermogram of sample PP415-P12 (FIG. 101) shows the loss of ˜4.9 wt.-% EtOH (with traces of water) from 25° C. to 250° C., most of it in a step from ˜160° C. to 190° C. Decomposition starts at temperatures T>250° C. The theoretical EtOH (b.p.=78° C.) content of a hemisolvate is 4.0 wt.-%.

Thus, the samples of class 3 seem to be isostructural solvates of 2PrOH, EtOH, and probably acetone with tightly bound solvent content. They could correspond to stoichiometric hemisolvates. It cannot be ruled out, however, that these forms are non-stoichiometric solvates.

As the Raman spectra and PXRD patterns within this class are very similar to each other, the structures might be essentially identical with only small distortions of the unit cell dimensions or small changes of atomic positions within the unit cell due to the incorporation of different solvent molecules.

TABLE 21 Crystallization experiments resulting in solid material of class 3 Sample Method Solvent/Mixture Characterization Drying PP415-P6 suspension 2PrOH Raman, PXRD, X equil. TG-FTIR PP415-P12 suspension  9:1 EtOH/H₂O Raman, PXRD, — equil. TG-FTIR PP415-P20 slow ~2:1 acetone/H₂O Raman, PXRD — cooling

j. Drying Experiments on Samples of Class 3

One of the samples of class 3 (PP415-P6), obtained from a suspension equilibration experiment in 2PrOH, was dried (as PP415-P25) under vacuum for several days (2-20 mbar, r.t. to 60° C., Table 22).

The TG-FTIR thermogram of this dried class 3 material, sample PP415-P25 (FIG. 102), shows the loss of ˜5.4 wt.-% 2PrOH from 50° C. to 250° C., most of it in a step from 170° C. to 190° C., another loss of ˜1.0 wt.-% 2PrOH from 290° C. to 320° C., and decomposition at temperatures T>320° C. Compared to the TG-FTIR of the original class 3 sample PP415-P6 (FIG. 103), with a solvent content of ˜5.4 wt.-% 2PrOH, the solvent content does not seem to have decreased significantly.

This material was dried further (as PP415-P33, Table 22) for three days under high vacuum and elevated temperatures (<1×10⁻³ mbar, 80° C.) with the aim to desolvate the solvate and to obtain a non-solvated, anhydrous form of 63415.

The TG-FTIR thermogram of this further dried class 3 material, sample PP415-P33 (FIG. 103) shows the loss of ˜4.2 wt.-% 2PrOH from 50° C. to 210° C., most of it in a step from 160° C. to 190° C., another loss of ˜0.5 wt.-% 2PrOH from 210° C. to 290° C., and decomposition at temperatures T>290° C.

Compared to the solvent content of the samples PP415-P6 and PP415-P25, the solvent content has decreased only from ˜5.4 wt.-% to ˜4.8 wt.-%.

TABLE 22 Drying experiments on samples of class 3 Starting Material Dried Material Solvent Drying Solvent Sample Content Conditions Sample Content Class PP415-P6 2PrOH r.t., ~3 mbar, PP415-P25 2PrOH 3 (~5.4%) ~5 d; 60° C., (~5.4%) 5-10 mbar, 2 × 1 h; 40-50° C., 5-20 mbar, ~1 d PP415-P25 2PrOH 80° C., PP415-P33 2PrOH 3 (~5.4%) <1 × 10⁻³ mbar, (~4.8%) 3 d

The FT-Raman spectra of class 3 (sample PP415-P6), of the dried material of class 3 (sample PP415-P25), and of the further dried material of class 3 (sample PP415-P33) are identical and show no changes (FIG. 104).

The PXRD patterns of class 3 (sample PP415-P6) and of the further dried material of class 3 (sample PP415-P33) do not show any significant differences, while there are few small shifts and differences from the pattern of the initially dried material of class 3 (sample PP415-P25, FIG. 105). All patterns correspond to class 3.

As the drying had no major effect on the solvent content, it is not surprising that the FT-Raman spectra and PXRD patterns of the dried materials do not show differences compared to the non-dried material.

Thus, class 3 is a class of isostructural solvates (2PrOH, EtOH, and probably acetone) with very tightly bound solvent molecules that could be removed only partially (˜5.4 wt.-% to ˜4.8 wt.-%) by the drying conditions applied here (up to 3 d at 1×10⁻³ mbar and 80° C.).

k. Class 4˜Acetonitrile Solvate

Class 4 was obtained only from a 7:3 MeCN/H₂O solvent mixture (Table 23). The experiment resulting in class 4 (PP415-P13) was repeated as PP415-P35 to prepare more material for further drying studies.

The FT-Raman spectrum (FIG. 72) and PXRD pattern (FIG. 75) of class 4 (sample PP415-P13) differ significantly from the spectra and patterns of classes 2, 3, and 5.

The TG-FTIR thermogram of class 4 (sample PP415-P13, FIG. 106) shows the loss of ˜3.4 wt.-% MeCN (with traces of water) from 25° C. to 270° C., most of it in a step from ˜180° C. to 210° C. Decomposition starts at temperatures T>270° C. Before the TG-FTIR experiments, the samples were dried briefly (for ˜5 min) under vacuum (10-20 mbar) to remove excess, unbound solvent. The theoretical MeCN (b.p.=81° C.) content of a hemisolvate is 3.6 wt.-%.

TABLE 23 Crystallization experiments resulting in solid material of class 4 Sample Method Solvent Characterization Drying PP415-P13 suspension 7:3 MeCN/H₂O Raman, PXRD, X equilibration TG-FTIR PP415-P35 suspension 7:3 MeCN/H₂O Raman, PXRD, X equilibration TG-FTIR

l. Drying Experiments on Class 4

The samples of class 4 obtained from suspension equilibration experiments in ˜7:3 MeCN/H₂O were dried under vacuum for several days or under N₂ flow (Table 24).

TABLE 24 Drying experiments on samples of class 4 Starting Material Dried Material Solvent Drying Solvent Sample Content Conditions Sample Content Class PP415-P13 MeCN r.t., ~3 mbar, PP415- MeCN 4 (~3.4%) ~5 d; 60° C., P26 (~2.8%) 5-10 mbar, 2 × 1 h; 40-50° C., 5-20 mbar, ~1 d PP415-P35 MeCN 80° C., PP415- MeCN/H₂O^(a) 4 (~2.9%) <1 × 10⁻³ mbar, P36 (~0.6%) 3 d PP415-P35 MeCN 80° C., PP415- MeCN/H₂O^(a) 4 (~2.9%) N₂ flow, 3 d P37 (~0.9%) ^(a)solvent content possibly MeCN and H₂O, but difficult to determine as amounts are small

The FT-Raman spectrum of the dried class 4 material (PP415-P26) is identical to the spectrum of class 4 (PP415-P13, FIG. 107).

The PXRD pattern of the dried class 4 material (PP415-P26) shows only very small differences from the pattern of class 4, sample PP415-P13 (FIG. 108). Some peaks seem better resolved, and peak intensities have shifted. No amorphization is observed. The pattern of PP415-P26 corresponds to class 4.

The TG-FTIR thermogram of the dried class 4 material, sample PP415-P26 (FIG. 109) shows the loss of ˜2.8 wt.-% MeCN from 170° C. to 250° C. and decomposition at temperatures T>300° C. Compared to the TG-FTIR of sample PP415-P13 (FIG. 106), the solvent content of the sample has decreased from 3.4 wt.-% to 2.8 wt.-%.

Thus, the sample seems to be a partially desolvated solvate. As not sufficient material remained for a second drying experiment with subsequent characterization, experiment PP415-P13 was repeated (as PP415-P35). More material of class 4 was prepared and two drying experiments were carried out with this freshly prepared material:

PP415-P36: drying under vacuum (<1×10⁻³ mbar) at 80° C. for three days

PP415-P37: drying under N₂ flow at 80° C. for three days

The FT-Raman spectra of these dried class 4 samples (PP415-P36 and -P37) correspond to the spectrum of class 4 (i.e., PP415-P35, FIG. 110).

The PXRD patterns (FIG. 111) of the class 4 material (sample PP415-P35) and the dried samples of class 4 (samples PP415-P36 and PP415-P37) are identical. The dried samples are crystalline.

The TG-FTIR thermograms of these dried samples of class 4 (FIG. 112 for PP415-P36 and FIG. 113 for PP415-P37) show only a small solvent content (MeCN and/or H₂O) of ˜0.6 wt.-% and ˜0.9 wt.-% for PP415-P36 and PP415-P37, respectively, in two steps from 25° C. to 280° C. Solvent content is possibly MeCN and H₂O, but is difficult to determine as amounts are small. Decomposition starts at temperatures T>280° C.

Thus, most of the solvent of this solvate could be removed without destroying the crystal structure. A crystalline, non-solvated form (or rather desolvated solvate) was obtained.

m. Further Characterization of the Dried and Desolvated Class 4

Drying of class 4 (MeCN solvate) resulted in a desolvated solvate with the solvent content reduced to <1 wt.-% (TG-FTIR).

No change in the structure occurred upon desolvation (FT-Raman and PXRD). No significant loss of the crystallinity was observed.

Thus, a non-solvated, crystalline form of 63415 was obtained, the only one known to date.

This desolvated class 4 material was characterized further by DVS and DSC.

The DVS isotherm (FIG. 114) shows that during initial equilibration time at 50% r.h. a mass gain of ˜0.4 wt.-% occurred. During the measurement, a gradual, reversible mass loss of ˜1.3 wt.-% occurred upon lowering the relative humidity from 50% r.h. to 0% r.h. Equilibrium was reached. Upon increasing the relative humidity to 95% r.h., a gradual mass gain of ˜0.8 wt.-% was observed (relative to the equilibration mass at 50% r.h.). Equilibrium was reached. After lowering the relative humidity to 50% r.h., the final mass remained 0.1 wt.-% below the equilibrated starting mass. The mass gain of ˜0.7 wt.-% upon increasing the relative humidity from 50% r.h. to 85% r.h. classified the sample as slightly hygroscopic.

The PXRD pattern of the sample after the measurement is unchanged compared to the pattern before the measurement (FIG. 115).

The DSC thermogram of a sample of desolvated class 4 material (FIG. 116) shows no glass transition attributable to the amorphous form, which would have been expected at ˜150° C., but instead a sharp endothermic peak with a maximum at T=196.1° C. (ΔH=29.31 J/g), probably corresponding to melting, and no decomposition up to 270° C.

In addition, a DSC experiment was carried out with a ˜1:1 mixture of the amorphous material, class 1, with the desolvated class 4 material to investigate if the amorphous material would transform and crystallize into the desolvated class 4, an event expected to occur (if at all) above the glass transition temperature of the amorphous form (T_(g)≈150° C.) and below the melting of the desolvated class 4 (T_(m)≈196° C.).

The DSC thermogram of the mixture (FIG. 117) shows an endothermic event with a peak at T=156.7° C. (ΔH=1.47 J/g) and a second endothermic event with a peak at 197.0° C. (ΔH=14.1 J/g). The first event could be attributable to the amorphous material (glass transition at T_(g)≈150° C.). The second event could correspond to the melting of the desolvated class 4 at T_(m)≈196° C. The heat of fusion (ΔH=14.1 J/g) of the mixture correlates well to half of the heat of fusion (ΔH=29.3 J/g) of the pure desolvated class 4.

No exothermic event in the temperature range between the glass transition and the melting corresponding to a possible crystallization of the amorphous material can be observed. Thus, no transformation of the amorphous form into the desolvated class 4 form seemed to have occurred on this timescale.

In yet another DSC experiment with a ˜1:1 mixture of the amorphous material, class 1, with the desolvated class 4 material, the heating was stopped at 173° C. (in between the glass transition and the melting) to allow time for a possible crystallization.

The DSC thermogram of the mixture (FIG. 118) shows an endothermic event with a peak at T=161.4° C. (ΔH=0.31 J/g) and a second endothermic event with a peak at 201.4° C. (ΔH=11.4 J/g). As in the first experiment, the heat of fusion of the second peak did not increase; no indications for a transformation of the amorphous form into the desolvated class 4 form are visible.

The curved baseline (−50° C. to 150° C.) is most likely an artifact (due to a bent sample holder lid).

n. Class 5—THF Solvate

Class 5 was obtained only from a 1:1 THF/H₂O solvent mixture (Table 25).

The FT-Raman spectrum (FIG. 71) and PXRD pattern (FIG. 75) of class 5 differs significantly from the spectra and patterns of classes 2, 3, and 4.

The TG-FTIR thermogram of class 5 (sample PP415-P14, FIG. 119) shows the loss of ˜36.1 wt.-% THF and H₂O from 25 to 200° C., most of it in a step from ˜100° C. to 130° C. Before the TG-FTIR experiments, the samples were dried briefly (for ˜5 min) under vacuum (10-20 mbar) to remove excess, unbound solvent. The loss of both THF and H₂O occur together in the same temperature range. Decomposition starts at temperatures T>300° C. The theoretical THF (b.p.=66° C.) content of a trisolvate is 28.1 wt.-%. Unfortunately, as the content of the two components cannot be quantified separately, the exact solvation state cannot be determined.

Details on the experiments and characterizations of samples PP415-P41 and PP415-P45 are provided.

TABLE 25 Crystallization experiments resulting in solid material of class 5 Sample Method Solvent Characterization Drying PP415-P14 suspension 1:1 THF/H₂O Raman, PXRD, X equilibration TG-FTIR PP415-P41^(b) suspension 1:1 THF/H₂O PXRD X equilibration PP415-P45^(b,c) suspension 1:1 THF/H₂O PXRD X equilibration ^(b)starting material: PP415-P40, class 2; in all other experiments in this table PP415-P1, class 1, was used as the starting material ^(c)3-g scale experiment instead of 100-mg scale

o. Drying Experiments on Samples of Class 5

The sample of class 5 (PP415-P14), obtained from a suspension equilibration experiment in ˜1:1 THF/H₂O, was dried (as PP415-P27) under vacuum for several days (2-20 mbar, r.t. to 60° C., Table 26).

TABLE 26 Drying experiments of samples of Class 5 Starting Material Dried Material Solvent Drying Solvent Sample Content Conditions Sample Content Class PP415- THF & H₂O r.t., ~3 mbar, PP415- — 1 (+5)^(a) P14 (~36 wt.-%) ~5 d; 60° C., P27 (~0.3 wt.-%) 5-10 mbar, 2 × 1 h; 40-50° C., 5-20 mbar, ~1 d ^(a)mainly amorphous, only few broad peaks with low S/N ratio

The FT-Raman spectrum of the dried material (PP415-P27) is different from the spectrum of class 5 (PP415-P14, FIG. 120) and, with its broadened peaks, resembles more the spectrum of class 1, the amorphous starting material, PP415-P1.

The PXRD pattern of the dried class 5 material (PP415-P27) shows only some broad, low intensity peaks with a low S/N ratio, indicating the poor crystallinity of the sample (FIG. 121). Some of the peaks could correspond to class 5, while others, i.e., at 7.35° 2θ, are new or shifted.

The TG-FTIR thermogram of the dried class 5 material (FIG. 122) shows a mass loss of ˜0.3 wt.-% from 25° C. to 290° C. and decomposition at temperatures T>290° C. The sample is anhydrous.

Thus, by drying under vacuum, the material has lost its solvent content and also much of its crystallinity.

8. Experiments to Prepare the Amorphous Form

Experiments with the aim to prepare the amorphous form, class 1, were carried out using class 2 material (PP415-P40, Table 8) as the starting material. Several strategies and methods were attempted:

-   -   Transformation of class 2 into class 5, followed by drying of         class 5 to obtain the amorphous form, class 1.     -   Preparation of the amorphous form, class 1, directly from class         2, if possible using ICH class 3 solvents.         Mainly amorphous material was prepared starting from class 2         material in a two-step process via class 5 on a 100-mg and 3-g         scale.

Further experiments were carried out with the aim to simplify the procedure to a one-step process, to avoid the ICH class 2 solvent THF, and to obtain fully amorphous material. The most promising method was found to be the precipitation from an acetone solution in a cold water bath. This direct method gives much better results than the two-step method via class 5.

a. Preparation of the Amorphous Form via Class 5

Crystallization experiments using class 2, PP415-P40, as the starting material were carried out with the aim to transform this heptane solvate into class 5 (likely THF solvate), followed by drying of class 5 to obtain the amorphous material (Table 27).

Class 5 is thought to be a good intermediate step, as it is easier to desolvate and amorphize than classes 2 or 3.

TABLE 27 Summary of experiments aimed at preparation of amorphous form, class 1, via class 5 material Step Sample Method Conditions Results 1 PP415-P41 suspension 1:1 THF/H₂O, 24° C., class 5 equil. 3 d ″ PP415-P45 suspension 1:1 THF/H₂O, r.t. 1 d class 5 equil. 2 PP415-P44a drying 100 mbar, 80° C., 2 d class 1^(a); 0.9 wt.-% THF ″ PP415-P46a drying 100 mbar, 80° C., 4 d class 1^(a); 0.4 wt.-% H₂O ^(a)mainly amorphous, only few broad peaks with low S/N ratio

b. Step 1: Transformation of Class 2 into Class 5

Transformation of the heptane solvate, class 2, into the THF solvate, class 5, was successfully carried out by suspending the PP415-P40 (heptane solvate) material in a (1:1) THF/H₂O mixture and equilibrating the suspension at r.t. (PP415-P41, 100 mg-scale). The resulting solid material corresponds to the THF solvate, class 5 (FIG. 123).

A first scale-up experiment from the mg-scale to the g-scale (×30, i.e., 3-g scale) was carried out analogous to PP415-P41: the class 2 heptane solvate starting material (PP415-P40) was equilibrated in THF/H₂O (1:1) for one day and successfully transformed into class 5, the THF solvate (PP415-P45, FIG. 124).

c. Step 2: Amorphization of Class 5 Material by Drying

The class 5 material (THF solvate) was dried at elevated temperature (80° C.) under vacuum (˜100 mbar) taking into account the conditions that can be used at the API MFG site.

After drying the material of the 100-mg scale experiment, PP415-P41, for one day at 80° C. and 100 mbar it transformed into mainly amorphous material (PP415-P44, FIG. 125). The PXRD pattern shows only some broad peaks with low intensity. After additional drying (80° C., 100 mbar) overnight, the intensity of these broad peaks is further reduced (PP415-P44a). The TG-FTIR of this material shows the loss of ˜0.9 wt.-% THF (with traces of water) gradually from 25° C. to 280° C. and decomposition at temperatures T>300° C. (FIG. 126).

The material of the 3-g scale experiment, PP415-P45, was also dried at 80° C. and 100 mbar (as PP415-P46). It transformed overnight into mainly amorphous material with only some broad peaks with low intensity (FIG. 127). After a total of four days of drying (80° C., 100 mbar), these broad peaks are still present (-P46a, FIG. 128). The TG-FTIR of this material shows no THF content, but the loss of ˜0.4 wt.-% water gradually from 25° C. to 250° C. and decomposition at temperatures T>250° C. (FIG. 129).

d. Obtaining the Amorphous Form Directly

The preparation of the amorphous form starting from class 2 material in the two-step process via class 5 was largely, but not fully, successful. Thus, further experiments were carried out with the aim to simplify the procedure to a one-step process, to avoid the use of ICH class 2 solvent THF, and to obtain fully amorphous material (Table 28).

The amorphous form, class 1, was prepared directly from the class 2 material in an evaporation experiment of a class 2 solution in THF under N₂ flow (PP415-P42, FIG. 129).

In an attempt to simulate an incompletely dried heptane/hexane solvate with a significant amount of remaining solvent, an evaporation of a class 2 solution in an 8:2 THF/hexane solution was carried out (hexane was used instead of heptane in order to have similar boiling points in the solvent mixture). However, the resulting solid corresponds to class 2, the class of the isostructural solvates, not to class 5 (PP415-P43, FIG. 130).

In order to avoid the ICH class 2 solvent THF, evaporation experiments were carried out in ICH class 3 solvents.

Evaporation of a class 2 solution in EtOAc under N₂ flow resulted in crystalline material with a PXRD pattern corresponding to class 2 (PP415-P47, FIG. 130). The TG-FTIR (FIG. 80) shows the class 2-typical two-step mass loss (total of ˜7.9 wt.-% EtOAc) at temperatures up to 240° C., indicating very tightly bound solvent molecules.

Evaporation in ethyl formate also gave crystalline class 2 material and not the amorphous form (PP415-P48, FIG. 131). The TG-FTIR (FIG. 78) shows the mass loss of ˜3.5 wt.-% ethyl formate, at first gradually and then in a clear step between 180° C. and 200° C. There might be further loss of ethyl formate concomitant with the decomposition at T>240° C.

However, class 2 material was successfully transformed into the amorphous form, class 1, by adding an acetone solution to a cold (5° C.) water bath (PP415-P49, FIG. 132).

This direct method for the preparation of the amorphous form gives better results and is a more promising route than the two-step process.

TABLE 28 Summary experiments aimed at obtaining the amorphous form directly from class 2 starting material Sample Method Solvent Condition Result PP415-P42 evaporation THF N₂ flow, 1 d class 1 PP415-P43 evaporation 8:2 THF/hexane N₂ flow, 1 d class 2 PP415-P47 evaporation EtOAc N₂ flow, 1 d class 2 PP415-P48 evaporation ethyl formate N₂ flow, 1 d class 2 PP415-P49 precipitation acetone H₂O bath class 1 at 5° C.

9. Instrumental—Typical Measurement Conditions

FT-Raman Spectroscopy:

Bruker RFS100 with OPUS 6.5 software; Nd:YAG 1064-nm excitation, Ge detector, 3500-100 cm⁻¹ range; typical measurement conditions: 100-300 mW nominal laser power, 64-128 scans, 2 cm⁻¹ resolution.

PXRD:

Stoe Stadi P; Mythen1K Detector; Cu—Kα radiation; standard measurement conditions: transmission; 40 kV and 40 mA tube power; curved Ge monochromator; 0.02° 2θ step size, 12 s or 60 s step time, 1.5-50.5° 2θ or 1.0-55° 2θ scanning range; detector mode: step scan; 1° 2θ or 6° 2θ detector step; standard sample preparation: 10 to 20 mg sample was placed between two acetate foils; sample holder: Stoe transmission sample holder; the sample was rotated during the measurement.

TG-FTIR:

Netzsch Thermo-Microbalance TG 209 with Bruker FT-IR Spectrometer Vector 22; aluminum crucible (with microhole), N₂ atmosphere, 10 K/min heating rate, 25-250° C. or 25-350° C. range.

DSC:

Perkin Elmer DSC 7; gold crucibles (closed or with microhole), sample filled in an N₂ environment, 10 K/min heating rate, −50 to 250° C. or 350° C. range, at times quench cooling (at −200 K/min) to −50° C. between scans.

DVS:

Projekt Messtechnik Sorptions Prüfsystem SPS 11-100n or Surface Measurement Systems DVS-1. The sample was placed on an aluminum or platinum holder on top of a microbalance and allowed to equilibrate for 2 h at 50% r.h. before starting the pre-defined humidity program:

(1) 50→0% r.h. (5%/h); 5 h at 0% r.h.

(2) 0→95% r.h. (5%/h); 5 h at 95% r.h.

(3) 95→50% r.h. (5%/h); 2 h at 50% r.h.

The hygroscopicity was classified based on the mass gain at 85% r.h. relative to the initial mass as follows: deliquescent (sufficient water adsorbed to form a liquid), very hygroscopic (mass increase of ≧15%), hygroscopic (mass increase <15% but ≧2%), slightly hygroscopic (mass increase <2% but ≧0.2%), or non-hygroscopic (mass increase <0.2%).

Solvents:

For all experiments, Fluka, Merck, or ABCR analytical grade solvents were used.

Approximate Solubility Determination:

Approximate solubilities were determined by a stepwise dilution of a suspension of about 10 mg of substance in 0.05 mL of solvent. If the substance was not dissolved by addition of a total of >10 mL solvent, the solubility is indicated as <1 mg/mL. Due to the experimental error inherent in this method, the solubility values are intended to be regarded as rough estimates and are to be used solely for the design of crystallization experiments.

Chemical Stability Determination:

Four samples of 1.0 mg of the PP415-P1 material in 1.0 mL of the respective solvent were prepared. The resulting suspensions/solutions were equilibrated in a temperature-controlled Eppendorf Thermomixer Comfort shaker for 7 d, 2 d, 24 h, and 6 h at 25° C. at a shaking rate of 500 rpm. If necessary, the solid phase was separated by filter centrifugation (0.5-μm PVDF membrane). The filtrates were diluted in the diluent (0.1% formic acid in MeCN) to concentrations ≦0.2 mg/mL (unknown and likely lower for suspensions) and examined using the HPLC method given in Table 29. As reference, the PP415-P1 material was diluted in the diluent to a concentration of 0.25 mg/mL and added to the beginning and end of the HPLC sequence.

HPLC Results

TABLE 29 HPLC method used for chemical stability determinations Column Zorbax Eclipse XDB-C18, 3 × 150 mm, 5 μm (CC19) Eluent A H₂O + 0.1% formic acid Eluent B MeCN + 0.1% formic acid Gradient  0 min 50% A 50% B 10.0 min 10% A 90% B 15.0 min  0% A 100% B  15.1 min 50% A 50% B 20.0 min 50% A 50% B Flow 0.75 mL/min Injection Volume 10 μL Wavelength 254 nm, 242 nm, 210 nm Acquisition time 20 min Run time 20 min Column 25° C. temperature Retention time 8.9-9.0 min

10. Abbreviations

Methods:

-   -   AUC area under the curve analysis     -   DSC differential scanning calorimetry     -   DVS dynamic vapor sorption     -   FT Raman Fourier-transform Raman spectroscopy     -   ¹H-NMR proton nuclear magnetic resonance spectroscopy     -   HPLC high-performance liquid chromatography     -   PXRD powder X-ray diffraction     -   TG-FTIR thermogravimetry coupled to Fourier transform infrared         spectroscopy

Chemicals:

-   -   1BuOH 1-butanol     -   CTAB cetyl trimethylammonium bromide     -   DCM dichloromethane     -   DEE diethyl ether     -   DMF N,N-dimethylformamide     -   EtOAc ethyl acetate     -   EtOH ethanol     -   IPE isopropyl ether     -   MeCN acetonitrile     -   MEK methyl ethyl ketone     -   MeOH methanol     -   PEG propylene glycol     -   PTFE polytetrafluoroethylene, Teflon     -   2PrOH 2-propanol, isopropanol     -   SDS sodium dodecyl sulfate     -   TBME tert-butyl methyl ether     -   TEA triethylamine     -   THF tetrahydrofuran     -   Tween 80 polyoxyethylene (80) sorbitan monooleate or polysorbate         80

Genes, Proteins, and Biological Parameters:

-   -   AIM antioxidant inflammation modulator     -   Akr1c1 aldo-keto reductase family 1, member c1     -   ALP alkaline phosphatase     -   ALT alanine transaminase     -   ARE antioxidant response element     -   AST aspartate transaminase     -   AUC area under the curve     -   BAL bronchoalveolar lavage     -   BALF bronchoalveolar lavage fluid     -   Bil bilirubin     -   BUN blood urea nitrogen     -   COPD chronic obstructive pulmonary disease     -   COX-2 cyclooxygenase-2     -   Cr creatine     -   CYP450 cytochrome P450     -   Eh-1 epoxide hydrolase 1     -   G6PD glucose-6 phosphate dehydrogenase     -   Gcic glutamate-cysteine ligase, catalytic subunit     -   Gclm glutamate-cysteine ligase, modifier subunit     -   Ggt1 gamma-glutamyltransferase     -   Glrx glutaredoxin-1     -   Glu glucose     -   GOT glutamic-oxaloacetic transaminase     -   GPT1 glutamic-pyruvate transaminase     -   Gpx3 glutathione peroxidase 3     -   GSH glutathione     -   GSR glutathione reductase     -   GSs glutathione synthetase     -   GST glutathione S-transferase     -   GSTa1 glutathione S-transferase alpha 1     -   GSTp1 glutathione S-transferase pi 1     -   Gy Gray     -   H6PD hexose-6-phosphate dehydrogenase     -   hERG human ether a-go-go-related gene     -   HMOX1 heme oxygenase (decycling) 1     -   HO-1 heme oxygenase     -   IFNγ interferon-gamma     -   IL interleukin     -   iNOS inducible nitric oxide synthase     -   IκBα nuclear factor of kappa light polypeptide gene enhancer in         B-cells inhibitor, alpha     -   KC mouse IL-8 related protein     -   Keap1 Kelch-like ECH associated protein-1     -   LPS lipopolysaccharide     -   ME1 malic enzyme 1     -   MPCE micronucleated polychromatic erythrocytes     -   Mrp metG-related protein     -   Mrps multidrug resistance-related proteins     -   NADPH nicotinamide adenine dinucleotide phosphate, reduced     -   NFκB nuclear factor of kappa-light-chain-enhancer of activated B         cells     -   NO nitric oxide     -   NQO1 NAD(P)H quinone oxidoreductase 1     -   Nrf2 nuclear factor (erythroid-derived)-like 2     -   p-IκBα phosphorylated IκBα     -   PBMC peripheral blood mononuclear cell     -   PCE polychromatic erythrocytes     -   PGD phosphogluconate dehydrogenase     -   PMN polymorphonuclear     -   RANTES regulated and normal T cell expressed and secreted     -   SOD1 superoxide dismutase 1     -   SRXN1 sulfiredoxin-1     -   TG total glycerides     -   TKT transketolase     -   TNFα tumor necrosis factor alpha     -   Txn thioredoxin     -   TXNRD 1 thioredoxin reductase 1     -   xCT solute carrier family 7, member 11

Misc:

-   -   API active pharmaceutical ingredient     -   aq. aqueous     -   b.p. boiling point     -   cryst. crystalline     -   decomp. decomposition     -   d day(s)     -   eq. equivalent     -   equil. equilibration     -   evap. evaporation     -   h hour(s)     -   mat. material     -   min minute(s)     -   m.p. melting point     -   MS molecular sieves     -   part. partially     -   precip. precipitation     -   r.h. relative humidity     -   rpm revolutions per minute     -   r.t. room temperature (˜25° C.)     -   S/N signal-to-noise (ratio)     -   solv. solvent     -   susp. suspension     -   T temperature     -   T_(g) glass transition temperature     -   theo. theoretical     -   vis. obs. visual observation     -   w week(s)     -   wt.-% weight percent

K. Further Tables

TABLE 30 List of Samples and Performed Experiments Sample Experimental Description Test Methods Result/Remarks PP415-P1 received ~5 g of 63415, batch # 0141-66-1, on Mar. FT-Raman: FT-Raman: used as reference for P1 25, 2011; MW = 554.7 g/mol, C₃₃H₄₄F₂N₂O₃ PP415P1.0 PXRD: amorphous, no crystalline PP415P1.1 peak pattern PXRD: 117a TG-FTIR: loss of ~0.9 wt.-% TG-FTIR: a4285 (~0.1 eq.) EtOH with traces of H₂O ¹H-NMR: from 25° C. to 200° C., decomposition Mar30-2011- at T >290° C. ktr/30 ¹H-NMR: agrees with structure, ~0.08 DSC: d_9840 eq. EtOH DVS: #0305_02 DSC: 1^(st) scan: Tg = 152.7° C. (ΔCp = post-DVS Raman: 0.72 J/g° C.); 2nd scan: Tg = 149.7° C. PP415P1_aDVS (ΔCp = 0.45 J/g° C.) post-DVS PXRD: DVS: slightly hygroscopic; Δm = 179a +0.4% (50%→85% r.h.); total mass gain of 2.1 wt.-% from 0% r.h. to 95% r.h. post-DVS Raman and PXRD: unchanged PP415-P2 stored material of PP415-P1 at 25° C. open over a PXRD: PXRD: all amorphous, correspond to saturated solution of NH₄NO₃ (i.e., at ~62% r.h.); 132a (-P2a) P1 examined samples after 1 w (PP415-P2a), 2 w (PP415-P2b), and 4 w 191a (-P2b) (PP415-P2c). 262a (-P2c) PP415-P3 stored material of PP415-P1 at 40° C. open over a PXRD: PXRD: all amorphous, correspond to saturated solution of NaCl (i.e., at ~75% r.h.); examined 133a (-P3a) P1 samples after 1 w (PP415-P3a), 2 w (PP415-P3b), and 4 192a (-P3b) w (PP415-P3c). 263a (-P3c) PP415-P4 stored material of PP415-P1 at 60° C. in a closed PXRD: PXRD: all amorphous, correspond to container; examined samples after 1 w (PP415-P4a), 2 w 134a (-P4a) P1 (PP415-P4b), and 4 w (PP415-P4c). 193a (-P4b) 264a (-P4c) PP415-P5 stored material of PP415-P1 at 80° C. in a closed PXRD: PXRD: all amorphous, correspond to container; examined samples after 1 w (PP415-P5a), 2 w 135a (-P5a) P1 (PP415-P5b), and 4 w (PP415-P5c). 194a (-P5b) 265a (-P5c) PP415-P6 suspended 97.7 mg of PP415-P1 in 0.4 mL of 2PrOH; FT-Raman: Raman: corresponds to class 3 obtained white suspension; equilibrated suspension at 22° C. PP415P6.0 PXRD: corresponds to class 3 shaking at 400 rpm; added stepwise a total of 0.5 mL PXRD: 225a TG-FTIR: loss of ~5.4 wt.-% 2PrOH of the solvent over the next couple of days; after 15 d TG-FTIR: a4323 from 25° C. to 250° C., most of it in a recovered solid material by filter centrifugation (0.20-μm step from ~170° C. to 190° C.; PTFE membrane); examined material by FT-Raman decomposition starts at T>250° C. spectroscopy and PXRD; dried material for 5 min under vacuum (10-20 mbar); examined material by TG-FTIR. PP415-P7 suspended 104.3 mg of PP415-P1 in 0.6 mL of FT-Raman: Raman: corresponds to class 2 1:2 EtOAc/heptane; obtained white suspension; PP415P7.0 PXRD: corresponds to class 2 equilibrated suspension at 22° C. shaking at 400 rpm; PXRD: 227a TG-FTIR: loss of ~7.5 wt.-% EtOAc added stepwise a total of 0.2 mL of the solvent mixture TG-FTIR: a4338 and heptane in two steps from over the next couple of days; after 15 d recovered solid ~100° C. to 290° C.; decomposition material by filter centrifugation (0.20-μm PTFE starts at T >290° C. membrane); examined material by FT-Raman spectroscopy and PXRD; dried material for 5 min under vacuum (10-20 mbar); examined material by TG-FTIR. PP415-P8 suspended 102.0 mg of PP415-P1 in 0.4 mL of 1:2 FT-Raman: Raman: corresponds to class 2 acetone/hexane; obtained white suspension; equilibrated PP415P8.0 PXRD: corresponds to class 2 suspension at 22° C. shaking at 400 rpm; added stepwise PXRD: 228a a total of 0.2 mL of the solvent mixture over the next couple of days; after 15 d recovered solid material by filter centrifugation (0.20-μm PTFE membrane); examined material by FT-Raman spectroscopy and PXRD. PP415-P9 suspended 102.6 mg of PP415-P1 in 0.4 mL of 1:3 FT-Raman: Raman: corresponds to class 2, toluene/diethyl ether; obtained white suspension; PP415P9.0 contains solvent signals equilibrated suspension at 22° C. shaking at 400 rpm; added stepwise a total of 0.2 mL of the solvent mixture over the next couple of days; after 15 d recovered solid material by filter centrifugation (0.20-μm PTFE membrane); examined material by FT-Raman spectroscopy. PP415-P10 suspended 102.5 mg of PP415-P1 in 0.2 mL of FT-Raman: Raman: corresponds to class 2 1:3 MeOH/TBME; obtained clear solution; equilibrated PP415P10.0 PXRD: corresponds to class 2 solution at 22° C. shaking at 400 rpm; after 1 d observed PXRD: 229a thick suspension; added 0.2 mL of the solvent mixture; continued equilibration of suspension at 22° C. shaking at 400 rpm; after a total of 15 d recovered solid material by filter centrifugation (0.20-μm PTFE membrane); examined material by FT-Raman spectroscopy and PXRD. PP415-P11 suspended 97.1 mg of PP415-P1 in 0.4 mL of 1:2 FT-Raman: Raman: corresponds to class 2, MEK/cyclohexane; obtained white suspension; PP415P11.0 contains solvent signals equilibrated suspension at 22° C. shaking at 400 rpm; after 15 d recovered solid material by filter centrifugation (0.20-μm PTFE membrane); examined material by FT-Raman spectroscopy. PP415-P12 suspended 98.6 mg of PP415-P1 in 0.2 mL of 9:1 FT-Raman: Raman: corresponds to class 3 EtOH/H₂O; obtained white suspension; equilibrated PP415P12.0 PXRD: corresponds to class 3 suspension at 22° C. shaking at 400 rpm; added stepwise PXRD: 230a TG-FTIR: loss of ~4.9 wt.-% EtOH a total of 0.2 mL of the solvent mixture over the next TG-FTIR: a4324 (with traces of water) from 25° C. to couple of days; after 15 d recovered solid material by 250° C., most of it in a step from filter centrifugation (0.20-μm PTFE membrane); ~160° C. to 190° C.; decomposition examined material by FT-Raman spectroscopy and starts at T>250° C. PXRD; dried material for 5 min under vacuum (10-20 mbar); examined material by TG-FTIR. PP415-P13 suspended 95.9 mg of PP415-P1 in 0.2 mL of 7.3 FT-Raman: Raman: corresponds to class 4, MeCN/H₂O; obtained two clear, separated phases; PP415P13.0 contains solvent signals equilibrated solution at 22° C. shaking at 400 rpm; after PXRD: 231a PXRD: corresponds to class 4 1 d observed thick suspension; added 0.2 mL of the TG-FTIR: a4321 TG-FTIR: loss of ~3.4 wt.-% MeCN solvent mixture; continued equilibration of suspension (with traces of water) from 25° C. to at 22° C. shaking at 400 rpm; after a total of 15 d 270° C., most of it in a step from recovered solid material by filter centrifugation (0.20-μm ~180° C. to 210° C.; decomposition PTFE membrane); examined material by FT-Raman starts at T>270° C. spectroscopy and PXRD; dried material for 5 min under vacuum (10-20 mbar); examined material by TG-FTIR. PP415-P14 suspended 95.8 mg of PP415-P1 in 0.2 mL of FT-Raman: Raman: corresponds to class 5, 9:1 THF/H₂O; obtained two clear, separated phases; PP415P14.0 contains solvent signals equilibrated solution at 22° C. shaking at 400 rpm; after PXRD: 232a PXRD: corresponds to class 5 1 d observed one clear phase; added 0.2 mL of H₂O; TG-FTIR: a4322 TG-FTIR: loss of ~36.1 wt.-% THF observed white precipitate; equilibrated suspension at 22° C. and H₂O from 25° C. to 200° C., most shaking at 400 rpm; after a total of 15 d recovered of it in a step from ~100° C. to 130° C.; solid material by filter centrifugation (0.20-μm PTFE decomposition starts at T >300° C. membrane); examined material by FT-Raman spectroscopy and PXRD; dried material for 5 min under vacuum (10-20 mbar); examined material by TG-FTIR. PP415-P15 dissolved 100.6 mg of PP415-P1 in 0.2 mL of 1:2 FT-Raman: Raman: corresponds to class 2, DCM/IPE; obtained clear solution; observed PP415P15.0 contains solvent signals precipitation of white solid in <1 min; added 0.2 mL of PXRD: 137a PXRD: corresponds to class 2 solvent mixture; covered vial with single-layer tissue and let solvent evaporate under ambient conditions; obtained wet, white solid material after several hours; examined solid by FT-Raman spectroscopy and PXRD. PP415-P16 dissolved 100.3 mg of PP415-P1 in 0.2 mL of 1:2 FT-Raman: FT-Raman: corresponds to class 1, MeOH/toluene; obtained clear solution; covered vial PP415P16.0 contains toluene solvent peaks with single-layer tissue and let solvent evaporate under ambient conditions; obtained glassy material after several days; examined material by FT-Raman spectroscopy. PP415-P17 dissolved 101.0 mg of PP415-P1 in 0.3 mL of 1:3 FT-Raman: Raman: corresponds to class 2, EtOAc/heptane; obtained clear solution; observed PP415P17.0 contains solvent signals precipitation of white solid in <1 min; added 0.2 mL of PXRD: 138a PXRD: corresponds to class 2 solvent mixture; covered vial with single-layer tissue and let solvent evaporate under ambient conditions; obtained wet, white solid material after several hours; examined solid by FT-Raman spectroscopy and PXRD. PP415-P18 dried material of PP415-P15 under vacuum (2-20 mbar) FT-Raman: Raman: corresponds to class 2 at r.t. for ~2 h; examined dry, white solid by FT-Raman PP415P18.0 PXRD: corresponds to class 2 spectroscopy, PXRD, and TG-FTIR. PXRD: 149a TG-FTIR: loss of ~7.0 wt.-% IPE in TG-FTIR: a4301 two steps from ~140° C. to ~250° C.; decomposition at T >250° C. PP415-P19 dried material of PP415-P17 under vacuum (2-20 mbar) FT-Raman: Raman: corresponds to class 2 at r.t. for ~2 h; examined dry, white solid by FT-Raman PP415P19.0 PXRD: corresponds to class 2 spectroscopy, PXRD, and TG-FTIR. PXRD: 150a TG-FTIR: loss of ~7.6 wt.-% heptane TG-FTIR: a4302 in two steps from ~140° C. to ~270° C.; decomposition at T >270° C. PP415-P20 suspended 98.8 mg of PP415-P1 in 2.0 mL of H₂O; FT-Raman: Raman: corresponds to class 3, heated suspension to 50° C.; added slowly and stepwise PP415P20.0 contains solvent signals 4.0 mL of acetone; obtained clear solution; heated PXRD: 226a PXRD: corresponds to class 3 solution to 55° C. and held at 55° C. for 30 min; slowly cooled in 4 h 10 min to 5° C. (at ~0.2 K/min); recovered solid by vacuum filtration (P4 pore size); examined solid by FT-Raman spectroscopy and PXRD. PP415-P21 suspended 100.9 mg of PP415-P1 in 2.0 mL of FT-Raman: Raman: corresponds to class 2 cyclohexane; heated suspension to 70° C.; added slowly PP415P21.0 PXRD: corresponds to class 2 and stepwise 0.5 mL of cyclohexane and 0.5 mL of PXRD: 218a TG-FTIR: loss of ~5.8 wt.-% EtOH; thin suspension became thicker due to additional TG-FTIR: a4326 cyclohexane in two steps from ~140° C. precipitation over course of solvent addition; heated to ~250° C.; decomposition at T >250° C. suspension to 75° C. and held at 75° C. for 30 min; slowly cooled in 5 h to 5° C. (at ~0.23 K/min); recovered solid by vacuum filtration (P4 pore size); examined solid by FT-Raman spectroscopy and PXRD; dried material for 5 min under vacuum (10-20 mbar); examined material by TG-FTIR. PP415-P22 suspended 151.1 mg of PP415-P1 in 1.5 mL of toluene; FT-Raman: Raman: corresponds to class 1, heated suspension to 70° C.; obtained clear solution; PP415P22.0 contains solvent signals added 0.5 mL of MeCN; heated solution to 75° C. and held at 75° C. for 30 min; slowly cooled in 5 h to 5° C. (at ~0.23 K/min); observed clear solution and no precipitation; stirred clear solution at 5° C. for 2 d; observed no precipitation; evaporated solvent under N₂ flow at r.t.; obtained glassy substance; examined it by FT-Raman spectroscopy. PP415-P23 suspended 150.6 mg of PP415-P1 in 1.5 mL of dioxane; FT-Raman: Raman: corresponds to class 1, heated suspension to 70° C.; obtained clear solution; PP415P23.0 contains solvent signals added 0.5 mL of EtOAc; heated solution to 75° C. and held at 75° C. for 30 min; slowly cooled in 5 h to 5° C. (at ~0.23 K/min); observed clear solution and no precipitation; stirred clear solution at 5° C. for 2 d; observed no precipitation; evaporated solvent under N₂ flow at r.t.; obtained glassy substance; examined it by FT-Raman spectroscopy. PP415-P24 suspended 99.4 mg of PP415-P1 in 0.3 mL of 1BuOH; FT-Raman: Raman: corresponds to class 2, heated suspension to 70° C.; obtained clear solution; PP415P24.0 contains solvent signals observed shortly thereafter precipitation of white solid; PXRD: 219a PXRD: corresponds to class 2 added 0.5 mL 1BuOH; still suspension; heated TG-FTIR: a4325 TG-FTIR: loss of ~16.6 wt.-% 1BuOH suspension to 75° C. and held at 75° C. for 30 min; slowly in a step from ~50° C. to ~160° C., cooled in 5 h to 5° C. (at ~0.23 K/min); recovered solid further loss of 1BuOH (6.6 wt.-%) in a by vacuum filtration (P4 pore size); examined solid by second step from 160° C. to 230° C.; FT-Raman spectroscopy and PXRD; dried material for 5 min decomposition at T >230° C. under vacuum (10-20 mbar); examined material by TG-FTIR. PP415-P25 dried material of PP415-P25 under vacuum: at 60° C. FT-Raman: Raman: corresponds to class 3 and ~5 mbar for ~1 h; at r.t. and ~3 mbar for 4.5 d; at PP415P25.0 PXRD: corresponds to class 3 60° C. and ~10 mbar for 1 h; at 40-50° C. and 5-20 mbar PXRD: 258a TG-FTIR: loss of ~5.4 wt.-% 2PrOH for ~20 h, examined solid by FT-Raman spectroscopy, TG-FTIR: a4337 from 50° C. to 250° C., most of it in a PXRD, and TG-FTIR. step from 170° C. to 190° C., another loss of ~1.0 wt.-% 2PrOH from 290° C. to 320° C.; decomposition at T >320° C. PP415-P26 dried material of PP415-P13 under vacuum: at 60° C. FT-Raman: Raman: corresponds to class 4 and ~5 mbar for ~1 h; at r.t. and ~3 mbar for 4.5 d; at 60° C. PP415P26.0 PXRD: corresponds to class 4 and ~10 mbar for 1 h; at 40-50° C. and 5-20 mbar for PXRD: 259a TG-FTIR: loss of ~2.8 wt.-% MeCN ~20 h, examined solid by FT-Raman spectroscopy, TG-FTIR: a4335 from 170° C. to 250° C.; decomposition PXRD, and TG-FTIR. at T >300° C. PP415-P27 dried material of PP415-P14 under vacuum: at 60° C. FT-Raman: Raman: seems to corresponds to a and ~5 mbar for ~1 h; at r.t. and ~3 mbar for 4.5 d; at 60° C. PP415P27.0 mixture of class 1 and class 5 and ~10 mbar for 1 h; at 40-50° C. and 5-20 mbar for PXRD: 260a PXRD: sample is only partially ~20 h, examined solid by FT-Raman spectroscopy, TG-FTIR: a4336 crystalline; the few, broad peaks PXRD, and TG-FTIR. correspond to class 5; thus corresponds to a mixture of the amorphous class 1 and class 5 TG-FTIR: loss of ~0.3 wt.-% from 25° C. to 290° C.; decomposition at T >290° C. PP415-P28 dried material of PP415-P21 under vacuum: at 60° C. FT-Raman: Raman: corresponds to class 2 and ~5 mbar for ~1 h; at r.t. and ~3 mbar for 4.5 d; at 60° C. PP415P28.0 PXRD: corresponds to class 2, sample and ~10 mbar for 1 h; at 40-50° C. and 5-20 mbar for PXRD: 261a less crystalline, as indicated by ~20 h, examined solid by FT-Raman spectroscopy, TG-FTIR: a4334 broader peaks PXRD, and TG-FTIR. TG-FTIR: loss of ~3.0 wt.-% cyclohexane in two steps from ~140° C. to ~250° C.; decomposition at T >250° C. PP415-P29 suspended 132.2 mg of PP415-P1 in 0.8 mL of 1:2 FT-Raman: Raman: corresponds to class 2 EtOAc/TEA; observed change in appearance of solid PP415P29.0 PXRD: corresponds to class 2 phase; agitated and sonicated; equilibrated suspension at PXRD: 282a TG-FTIR: loss of ~5.1 wt.-% EtOAc 24° C. shaking at 500 rpm; after 4 d recovered solid TG-FTIR: a4346 and TEA from ~50° C. to ~220° C., material by filter centrifugation (0.20-μm PTFE most of it in a step from 180° C. to 210° C.; membrane); examined material by FT-Raman decomposition at T >220° C. spectroscopy and PXRD; dried material for 5 min under vacuum (10-20 mbar); examined material by TG-FTIR. PP415-P30 dried material of PP415-P7 under vacuum at 50-70° C. FT-Raman: Raman: corresponds to class 2 and 1-10 mbar for 3 days; examined solid by FT-Raman PP415P30.0 PXRD: corresponds to class 2 spectroscopy, PXRD, and TG-FTIR. PXRD: 290a TG-FTIR: loss of ~2.1 wt.-% heptane TG-FTIR: a4347 (and some EtOAc) in two steps from ~50° C. to ~250° C.; decomposition at T >250° C. PP415-P31 suspended 137.6 mg of PP415-P1 in 2 mL of 9:1 FT-Raman: Raman: corresponds to class 1 H₂O/PEG 400; obtained white suspension; equilibrated PP415P31.0 PXRD: amorphous, corresponds to suspension at 24° C. shaking at 400 rpm; after 5 d PXRD: 320a class 1 recovered solid material by vacuum filtration; washed solid three times with small amount of H₂O; examined material by FT-Raman spectroscopy and PXRD. PP415-P32 dried material of PP415-P19 under vacuum at 80° C. and FT-Raman: Raman: corresponds to class 2 <1 × 10⁻³ mbar; after 1 d examined material by TG-FTIR PP415P32.0 PXRD: corresponds to class 2, less (a4362); continued drying; after a total of 3 d examined PXRD: 331a crystalline material by TG-FTIR (a4365), FT-Raman spectroscopy, (P32A) TG-FTIR P32: loss of 2.8 wt.-% and PXRD as P32A. TG-FTIR: heptane (25-250° C.), most of it in a a4362(P32) step from 170° C. to 200° C.; a4365 (P32A) decomposition at T >250° C. TG-FTIR P32A: loss of 2.2 wt.-% heptane (25-250° C.), most of it in a step from 170° C. to 200° C.; decomposition at T >250° C. PP415-P33 dried material of PP415-P19 under vacuum at 80° C. and FT-Raman: Raman: corresponds to class 3 <1 × 10−3 mbar; after 3 d examined material by FT- PP415P33.0 PXRD: corresponds to class 3 Raman spectroscopy, PXRD and TG-FTIR. PXRD: 332a TG-FTIR: loss of ~4.2 wt.-% 2PrOH TG-FTIR: a4366 (50-210° C.), most of it in a step from 160° C. to 190° C., another loss of ~0.5 wt.- % 2PrOH (210° C. to 290° C.); decomposition at T >290° C. PP415-P34 dried material of PP415-P19 under vacuum at 80° C. and FT-Raman: Raman: corresponds to class 2 <1 × 10−3 mbar; after 3 d examined material by FT- PP415P34.0 PXRD: corresponds to class 2, less Raman spectroscopy, PXRD and TG-FTIR. PXRD: 333a crystalline TG-FTIR: a4367 TG-FTIR: loss of ~2.3 wt.-% cyclohexane in two steps from 25° C. to 270° C.; decomposition at T >270° C. PP415-P35 suspended 158.4 mg of PP415-P1 in 0.2 mL of FT-Raman: Raman: corresponds to class 4, MeCN/H₂O obtained two clear, separated phases; PP415P35.0 contains solvent signals equilibrated solution at 24° C. shaking at 400 rpm; after PXRD: 326a PXRD: corresponds to class 4 3 d observed thick suspension; added 0.1 mL of the TG-FTIR: a4363 TG-FTIR: loss of 2.9 wt.-% MeCN solvent mixture; continued equilibration of suspension from 25° C. to 250° C.; decomposition at 24° C. shaking at 400 rpm; after a total of 5 d at T >250° C. recovered solid material by filter centrifugation (0.20-μm PTFE membrane); examined material by FT-Raman spectroscopy; dried material for 10 min under vacuum (10-20 mbar); examined material by PXRD and TG- FTIR. PP415-P36 dried material of PP415-P35 under vacuum at 80° C. and FT-Raman: Raman: corresponds to class 4 <1 × 10⁻³ mbar; after 3 d examined material by FT- PP415P36.0 PXRD: corresponds to class 4 Raman spectroscopy, PXRD and TG-FTIR. PXRD: 339a TG-FTIR: loss of ~0.6 wt.-% TG-FTIR: a4369 (probably H₂O and/or MeCN) in two steps from 25° C. to 280° C.; decomposition at T >280° C. PP415-P37 dried material of PP415-P35 under N₂ flow at 80° C.; FT-Raman: Raman: corresponds to class 4 after 3 d examined material by FT-Raman spectroscopy, PP415P37.0 PXRD: corresponds to class 4 PXRD, TG-FTIR, DSC, and DVS. PXRD: 340a TG-FTIR: loss of ~0.9 wt.-% TG-FTIR: a4370 (probably H2O and/or MeCN) in two DSC: d_9907 steps from 25° C. to 280° C.; DVS: dvs1176 decomposition at T >280° C. post-DVS PXRD: DSC: sharp endothermic peak at T = 363a 196.1° C. (ΔH = 29.31 J/g); no decomposition up to 270° C. DVS: slightly hygroscopic; Δm = +0.7% (50%→85% r.h.); total mass gain of 2.1 wt.-% from 0% r.h. to 95% r.h. post-DVS PXRD: corresponds to class 4 PP415-P38 DSC experiment: combined 1.275 mg of PP415-P1 and DSC: d_9917 DSC 1.344 mg of PP415-P36; equilibrated for 3 min under N₂; heated sample from −50° C. to 270° C. at 10 K/min. PP415-P39 DSC experiment: combined 2.17 mg of PP415-P1 and DSC: d_9923 DSC 2.20 mg of PP415-P36; mixed solids using a spatula; equilibrated for 3 min under N₂; heated sample from −50° C. to 173° C. at 10 K/min; held at 173° C. for 30 min; heated from 173° C. to 270° C. at 10 K/min. PP415-P40 received ~5 g of 63415, batch #: 2083-69-DC on May PXRD: 390a PXRD: corresponds to class 2 27, 2011; MW = 554.7 g/mol, C₃₃H₄₄F₂N₂O₃ PP415-P41 suspended 101.3 mg of PP415-P40 in 0.20 mL of PXRD: 400a PXRD: corresponds to class 5 THF/H₂O (1:1); obtained white suspension; equilibrated suspension at 24° C.; after 3 days recovered solid by filter centrifugation (0.2-μm PTFE membrane); dried solid material under vacuum for 5 min; examined solid by PXRD. PP415-P42 dissolved 104.6 mg of PP415-P40 in 0.20 mL of THF; PXRD: 405a PXRD: amorphous (class 1) obtained clear solution; evaporated solvent under N₂ flow overnight; obtained white solid; examined solid by PXRD. PP415-P43 dissolved 101.8 mg of PP415-P40 in 0.20 mL of PXRD: 429a PXRD: corresponds to class 2 THF/hexane (8:2); obtained clear solution; evaporated solvent under N2 flow overnight; obtained white solid; examined solid by PXRD. PP415-P44 dried material of PP415-P41 under vacuum (~100 mbar) PXRD: 474a, PXRD: both mainly amorphous (class at 80° C.; examined solid after 1 day by PXRD (474a); 482a 1), some broad peaks with low continued drying overnight; examined solid again by TG-FTIR: a4401 intensity PXRD (482a) and TG-FTIR. TG-FTIR: ~0.9 wt.-% THF 25-280° C., decomposition at T >300° C. PP415-P45 suspended 3.03 g of PP415-P40 in 6.0 mL of THF/H2O PXRD: 471a PXRD: corresponds to class 5 (1:1); obtained white suspension; equilibrated suspension at r.t.; after 1 day recovered small aliquot by filter centrifugation and examined it by PXRD; recovered solid of whole sample by vacuum filtration; dried sample for 10 min under vacuum (~10 mbar). PP415-P46 dried material of PP415-P45 under vacuum (~100 mbar) PXRD: 481a, PXRD: both mainly amorphous (class at 80° C.; examined solid after drying overnight by 496a 1), some broad peaks with low PXRD (481a); continued drying; after 4 days examine TG-FTIR: a4410 intensity solid as PP415-P46a by PXRD (496a) and TG-FTIR. TG-FTIR: ~0.4 wt.-% H₂O 25-250° C., decomposition at T >250° C. PP415-P47 dissolved 101.8 mg of PP415-P40 in 0.4 mL of EtOAc; PXRD: 492a PXRD: corresponds to class 2 obtained clear solution; evaporated solvent under N₂ TG-FTIR: a4412 TG-FTIR: ~6.2 wt.-% EtOAc 25-170° C., flow overnight; obtained white solid; examined solid by 1.7 wt.-% EtOAc 170-240° C., PXRD and TG-FTIR. decomposition at T >240° C. PP415-P48 dissolved 101.1 mg of PP415-P40 in 0.4 mL of ethyl PXRD: 493a PXRD: corresponds to class 2 formate; obtained clear solution; evaporated solvent TG-FTIR: a4413 TG-FTIR: ~3.5 wt.-% ethyl formate under N₂ flow overnight; obtained white solid; 25-200° C., decomposition at T >200° C. examined solid by PXRD and TG-FTIR. PP415-P49 dissolved 205.3 mg of PP415-P40 in 0.3 mL of acetone; PXRD: 593a PXRD: amorphous (class 1) obtained clear solution; added dropwise to 30.0 mL of H₂O (pre-cooled to 5° C.); obtained thin white suspension; stirred thin suspension at 5° C. overnight; obtained thicker white suspension; recovered solid by vacuum filtration (pore size P4); obtained 188.3 mg of white solid; examined solid by PXRD.

TABLE 31 Parameters of FIG. 51 NOx Levels (% vs LPS Controls) Compound 13 mg/kg 25 mg/kg 50 mg/kg RTA 405 * 44% 26% 18% 63415 30% 18% 16%

TABLE 32 63415: Primary In Vivo ADMET - Key Primary ADMET Assays and Endpoints Assay Key Endpoints 14-day mouse toxicity Tolerability, body weight, clinical chemistry Tissue distribution Nrf2 target gene mRNA expression & enzyme activation in liver 14-day rat toxicity Tolerability, body weight, clinical chemistry, & limited histopathology Tissue distribution and plasma TK Nrf2 target gene mRNA expression & enzyme activation in liver 14-day monkey toxicity Tolerability, body weight, clinical chemistry, & limited histopathology Tissue distribution and plasma TK Nrf2 target gene mRNA expression and enzyme activation in multiple tissues & PBMCs

TABLE 33 Parameters of FIG. 54 Vehicle 63415 Dose (mg/kg) 0 10 30 100 ALT (U/L) 100 39 63 91 AST (U/L) 156 98 147 167 ALP (U/L) 120 131 110 98 Tot Bil (mg/dL) <0.2 <0.2 <0.2 <0.2 BUN (mg/dL) 17 15 15 15 Cr (mg/dL) <0.2 <0.2 <0.2 <0.2 Glu (mg/dL) 288 307 285 273

TABLE 34 63415 is Negative for Genotoxicity in the In Vivo Micronucleus Study Change Number of PCE/Total from Number of MPCE/ Treatment Erythrocytes Control MPCE/1000 PCE PCE (n = 5/group) (Mean +/− SD) (%) (Mean +/− SD) Scored 24-h timepoint Sesame Oil 0.588 ± 0.04 — 0.2 ± 0.27 2/10000  125 mg/kg 0.543 ± 0.03 −8 0.3 ± 0.27 3/10000  250 mg/kg 0.520 ± 0.06 −12 0.3 ± 0.27 3/10000  500 mg/kg 0.426 ± 0.07 −28 0.0 ± 0.00 0/10000 1000 mg/kg 0.498 ± 0.05 −15 0.2 ± 0.27 2/10000 1500 mg/kg 0.499 ± 0.06 −15 0.4 ± 0.22 4/10000 2000 mg/kg 0.531 ± 0.05 −10 0.2 ± 0.27 2/10000 48-h timepoint Sesame Oil 0.526 ± 0.05 — 0.3 ± 0.27 3/10000  125 mg/kg 0.453 ± 0.03 −14 0.2 ± 0.27 2/10000  250 mg/kg 0.391 ± 0.02 −26 0.2 ± 0.27 2/10000  500 mg/kg 0.339 ± 0.05 −36 0.3 ± 0.45 3/10000 1000 mg/kg 0.344 ± 0.04 −35 0.1 ± 0.22 1/10000 1500 mg/kg 0.376 ± 0.05 −39 0.4 ± 0.42 4/10000 2000 mg/kg 0.360 ± 0.03 −32 0.1 ± 0.22 1/10000

TABLE 35 Parameters of FIG. 35 ALT AST ALP Tot Bil BUN Cr Tot Prot Albumin Glucose Chol TG Treatment Day (U/L) (U/L) (U/L) (mg/dL) (mg/dL) (mg/dL) (g/dL) (g/dL) (mg/dL) (mg/dL) (mg/dL) Vehicle BL 30 29 320 0.15 23 0.63 7.2 4.1 87 124 52 Day 14 37 37 345 0.23 18 0.63 6.9 4.1 63 130 64  10 mg/kg BL 46 32 351 0.18 35 0.78 7.4 4 74 146 51 Day 14 46 38 382 0.23 27 0.68 7.2 4 39 144 82  30 mg/kg BL 32 32 409 0.18 23 0.7 7.3 4.2 85 125 47 Day 14 47 43 416 0.2 20 0.58 7.2 4 53 122 64 100 mg/kg BL 32 35 381 0.15 24 0.7 6.9 4 96 137 37 Day 14 43 37 390 0.18 24 0.55 6 3.2 32 93 61

TABLE 36 In Vitro Activity of 63415 and 63355 63415 63355 NO IC₅₀ (nM), RAW264.7 4.0 ± 1   0.63 ± 0.06 WST-1 IC₅₀ (nM), RAW264.7 125 150 NQO1-ARE (fold at 62.5 nM in 5.3 ± 1.0 6.5 ± 0.9 HuH7)

TABLE 37 Parameters of FIG. 52 Compound Plasma Whole Blood Brain Liver Lung Kidney RTA 405 (nM) 130 1165 93 1143 1631 2357 63415 (nM) 51 679 1081 985 533 1604

TABLE 38 Parameters of FIG. 53 Compound Liver Lung Kidney RTA 405 1.93 1.48 8.25 63415 10.9 1.75 10.9

All of the compounds, polymorphs, formulations, and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compounds, polymorphs, formulations, and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compounds, polymorphs, formulations, and methods, as well as in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit, and scope of the invention. More specifically, it will be apparent that certain agents which are both chemically and physiologically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.

REFERENCES

The following references to the extent that they provide exemplary procedural or other details supplementary to those set forth herein, are specifically incorporated herein by reference.

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What is claimed is:
 1. A compound of the formula:

or a pharmaceutically acceptable salt thereof.
 2. A polymorphic form of a compound of the formula:

wherein the polymorphic form has an X-ray powder diffraction pattern (CuKα) comprising a halo peak at about 14° 2θ.
 3. The polymorphic form of claim 2, wherein the X-ray powder diffraction pattern (CuKα) further comprises a shoulder peak at about 8° 2θ.
 4. The polymorphic form of claim 2, wherein the X-ray powder diffraction pattern (CuKα) is as shown in FIG.
 59. 5. The polymorphic form of claim 2, further having a T_(g) from about 150° C. to about 155° C.
 6. The polymorphic form of claim 2, further having a differential scanning calorimetry (DSC) curve comprising an endotherm centered from about 150° C. to about 155° C.
 7. The polymorphic form of claim 2, having a differential scanning calorimetry (DSC) curve as shown in FIG.
 62. 8. A polymorphic form of a compound of the formula:

wherein the polymorphic form is a solvate having an X-ray powder diffraction pattern (CuKα) comprising significant peaks at about 5.6, 7.0, 10.6, 12.7, and 14.6° 2θ.
 9. The polymorphic form of claim 8, wherein the X-ray powder diffraction pattern (CuKα) is as shown in FIG. 75, top pattern.
 10. A polymorphic form of a compound of the formula:

wherein the polymorphic form is a solvate having an X-ray powder diffraction pattern (CuKα) comprising significant peaks at about 7.0, 7.8, 8.6, 11.9, 13.9 (double peak), 14.2, and 16.0° 2θ.
 11. The polymorphic form of claim 10, wherein the X-ray powder diffraction pattern (CuKα) is as shown in FIG. 75, second pattern from top.
 12. A polymorphic form of a compound of the formula:

wherein the polymorphic form is an acetonitrile hemisolvate having an X-ray powder diffraction pattern (CuKα) comprising significant peaks at about 7.5, 11.4, 15.6, and 16.6° 2θ.
 13. The polymorphic form of claim 12, wherein the X-ray powder diffraction pattern (CuKα) is as shown in FIG. 75, second pattern from bottom.
 14. The polymorphic form of claim 12, further having a T_(g) of about 196° C.
 15. The polymorphic form of claim 12, further having a differential scanning calorimetry (DSC) curve comprising an endotherm centered at about 196° C.
 16. The polymorphic form of claim 12, having a differential scanning calorimetry (DSC) curve as shown in FIG.
 116. 17. A polymorphic form of a compound of the formula:

wherein the polymorphic form is a solvate having an X-ray powder diffraction pattern (CuKα) comprising significant peaks at about 6.8, 9.3, 9.5, 10.5, 13.6, and 15.6° 2θ.
 18. The polymorphic form of claim 17, wherein the X-ray powder diffraction pattern (CuKα) is as shown in FIG. 75, bottom pattern.
 19. A pharmaceutical composition comprising: an active ingredient consisting of a compound of claim 1, and a pharmaceutically acceptable carrier.
 20. A method of treating a condition associated with inflammation or oxidative stress, selected from the group consisting of prostate cancer, dermatitis, sepsis, pulmonary inflammation, pulmonary fibrosis, COPD, asthma, mucositis, and ocular inflammation, in a patient in need thereof, comprising administering to the patient a therapeutically effective amount of the pharmaceutical composition of claim
 19. 21. The method of claim 20, wherein the dermatitis is radiation-induced dermatitis.
 22. The method of claim 20, wherein the mucositis is mucositis resulting from radiation therapy or chemotherapy.
 23. A method of reducing the duration and/or severity of radiation-induced oral mucositis or radiation-induced dermatitis in a patient in need of acute radiation treatment comprising administering to the patient a therapeutically effective amount of the pharmaceutical composition of claim 19 prior to and/or after said acute radiation treatment. 